userlibandfileserver/fileserver/smassstorage/scsiprot.cpp
author hgs
Mon, 11 Oct 2010 17:54:41 +0100
changeset 286 48e57fb1237e
parent 90 947f0dc9f7a8
permissions -rw-r--r--
201039_11

// Copyright (c) 2004-2010 Nokia Corporation and/or its subsidiary(-ies).
// All rights reserved.
// This component and the accompanying materials are made available
// under the terms of the License "Eclipse Public License v1.0"
// which accompanies this distribution, and is available
// at the URL "http://www.eclipse.org/legal/epl-v10.html".
//
// Initial Contributors:
// Nokia Corporation - initial contribution.
//
// Contributors:
//
// Description:
//

#include <e32std.h>
#include "mtransport.h"
#include "mprotocol.h"
#include "scsiprot.h"
#ifdef MSDC_MULTITHREADED
#include "rwdrivethread.h"
#endif // MSDC_MULTITHREADED

#include "OstTraceDefinitions.h"
#ifdef OST_TRACE_COMPILER_IN_USE
#include "scsiprotTraces.h"
#endif

// Helper macros
#define LBA(x) static_cast<TUint32>((x[3] << 24) | (x[4] << 16) | (x[5] << 8) | x[6])
#define LEN(x) static_cast<TUint16>((x[8] << 8) | x[9])


static const TUint32 KDefaultBlockSize = 0x200;  //default block size for FAT

static const TUint KUndefinedLun = 0xFFFF;

static const TUint8 KAllPages = 0x3F;

static const TUint8 KChangeableValues = 0x1;
static const TUint8 KDefaultValues = 0x2;

/**
Default constructor for TSenseInfo
*/
TSenseInfo::TSenseInfo()
    : iSenseCode(ENoSense),
      iAdditional(EAscNull),
      iQualifier(EAscqNull)
    {}


/**
Set sense with no additional info.

@param aSenseCode sense key
*/
void TSenseInfo::SetSense(TSenseCode aSenseCode)
    {
    iSenseCode = static_cast<TUint8>(aSenseCode);
    iAdditional = EAscNull;
    iQualifier = EAscqNull;
    OstTraceExt3(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_SETSENSE1, "    SENSE CODE %d ASC %d ASC %d", iSenseCode, iAdditional, iQualifier);
    }


/**
Set sense with additional info.

@param aSenseCode sense key
@param aAdditional additional sense code (ASC)
*/
void TSenseInfo::SetSense(TSenseCode aSenseCode, TAdditionalCode aAdditional)

    {
    iSenseCode = static_cast<TUint8>(aSenseCode);
    iAdditional = static_cast<TUint8>(aAdditional);
    iQualifier = EAscqNull;
    OstTraceExt3(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_SETSENSE2, "    SENSE CODE %d ASC %d ASC %d", iSenseCode, iAdditional, iQualifier);
    }


/**
Set sense with additional info and qualifier.

@param aSenseCode sense key
@param aAdditional additional sense code (ASC)
@param aQualifier additional sense code qualifier (ASCQ)
*/
void TSenseInfo::SetSense(TSenseCode aSenseCode,
                          TAdditionalCode aAdditional,
                          TAdditionalSenseCodeQualifier aQualifier)
    {
    iSenseCode = static_cast<TUint8>(aSenseCode);
    iAdditional = static_cast<TUint8>(aAdditional);
    iQualifier = static_cast<TUint8>(aQualifier);
    OstTraceExt3(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_SETSENSE3, "    SENSE CODE %d ASC %d ASC %d", iSenseCode, iAdditional, iQualifier);
    }


//-----------------------------------------------

/**
Creates the CScsiProtocol object.  Called during controller initialisation.

@param aDriveManager reference to the drive manager object
*/
CScsiProtocol* CScsiProtocol::NewL(CDriveManager& aDriveManager)
    {
    CScsiProtocol* self = new (ELeave) CScsiProtocol(aDriveManager);
    CleanupStack::PushL(self);
    self->ConstructL();
    CleanupStack::Pop();
    return self;
    }

/**
c'tor

@param aDriveManager reference to the drive manager object
*/
CScsiProtocol::CScsiProtocol(CDriveManager& aDriveManager):
    iDriveManager(aDriveManager),
    iLastCommand(EUndefinedCommand),
    iLastLun(KUndefinedLun),
    iMediaWriteSize(KDefaultMediaWriteSize)
    {
#ifdef USB_TRANSFER_PUBLISHER
    iWriteTransferPublisher = CUsbWriteTransferPublisher::NewL(iBytesWritten);
    iReadTransferPublisher = CUsbReadTransferPublisher::NewL(iBytesRead);

    for (TUint i = 0; i < KUsbMsMaxDrives; i++)
        {
        iBytesRead[i] = 0;
        iBytesWritten[i] = 0;
        }
#else
    iWriteTransferPublisher = CDriveWriteTransferPublisher::NewL(aDriveManager.iDrives);
    iReadTransferPublisher = CDriveReadTransferPublisher::NewL(aDriveManager.iDrives);
#endif
    }


CScsiProtocol::~CScsiProtocol()
    {
#ifdef MSDC_MULTITHREADED
    OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_DES, "Deleting Drive Threads");
    delete iWriteDriveThread;
    delete iReadDriveThread;
#endif // MSDC_MULTITHREADED

    delete iWriteTransferPublisher;
    delete iReadTransferPublisher;
    }


void CScsiProtocol::ConstructL()
    {
#ifdef MSDC_MULTITHREADED
    OstTrace0(TRACE_SMASSSTORAGE, _CSCSIPROTOCOL, "Creating Drive Threads");
    iWriteDriveThread = CWriteDriveThread::NewL();
    iReadDriveThread = CReadDriveThread::NewL();
#endif // MSDC_MULTITHREADED
    }


/**
Associates the transport with the protocol. Called during initialisation of the controller.

@param aTransport pointer to the transport object
*/
void CScsiProtocol::RegisterTransport(MTransportBase* aTransport)
    {
    iTransport = aTransport;
    }


/**
Called by the Transport when it detects that the USB device is either running
at High Speed or is at least capable of HS operation. The Protocol can use this
information (for instance) to select the optimal write block size to use.

This function is preferably called before actual MS data transfer operation
starts, and usually only once.

*/
void CScsiProtocol::ReportHighSpeedDevice()
    {
    iMediaWriteSize = KHsMediaWriteSize;
    OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_REPORTHIGHSPEEDDEVICE,
              "HS Device reported: SCSI will use 0x%x bytes disk write size", iMediaWriteSize);
    }


TInt CScsiProtocol::SetScsiParameters(TMassStorageConfig aConfig)
    {
    iConfig = aConfig;
    return KErrNone;
    }

#ifdef MSDC_MULTITHREADED

void CScsiProtocol::ProcessWriteComplete (TUint8* aAddress, TAny* aPtr)
    {
    ((CScsiProtocol*)aPtr)->iTransport->ProcessReadData(aAddress);
    }

void CScsiProtocol::InitializeBufferPointers(TPtr8& aDes1, TPtr8& aDes2) // Todo Change name later - InitializeReadBufferSomething
    {
    iReadDriveThread->iThreadContext->iBuffer.SetUpReadBuf(aDes1, aDes2);
    }
#endif

/**
Called by the transport layer when a packet is available for decoding.
If an error occurs, the sense code is updated and EFalse is returned.

@param aData

@return  ETrue if command was decoded and executed successfully
*/
TBool CScsiProtocol::DecodePacket(TPtrC8& aData, TUint aLun)
    {
    TUint command = aData[1];

    if (command != ERequestSense)
        {
        iSenseInfo.SetSense(TSenseInfo::ENoSense);
        }

    OstTraceExt2(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_DECODEPACKET, "Command=0x%x LUN=%d", command, aLun);
    switch (command)
        {
        case ETestUnitReady:
            HandleUnitReady(aLun);
            break;

        case ERequestSense:
            HandleRequestSense(aData);
            break;

        case EInquiry:
            HandleInquiry(aData, aLun);
            break;

        case EModeSense6:
            HandleModeSense6(aData, aLun);
            break;

        case EModeSense10:
            HandleModeSense10(aData, aLun);
            break;

        case EStartStopUnit:
            HandleStartStopUnit(aData, aLun);
            break;

        case EPreventMediaRemoval:
            HandlePreventMediaRemoval(aData, aLun);
            break;

        case EReadCapacity:
            HandleReadCapacity(aData, aLun);
            break;

        case ERead10:
            HandleRead10(aData, aLun);
            break;

        case EWrite10:
            HandleWrite10(aData,aLun);
            break;

        case EVerify10:
            HandleVerify10(aData, aLun);
            break;

        case EReadFormatCapacities:
            HandleReadFormatCapacities(aLun);
            break;

        default:
            iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::EInvalidCmdCode);
        }
    return(iSenseInfo.SenseOk());
    }


/**
Checks if drive ready

@param aLun Logic unit number
@return pointer to drive correspondent to LUN if drive mounted and ready, NULL otherwise
*/
CMassStorageDrive* CScsiProtocol::GetCheckDrive(TUint aLun)
    {
    TInt err=KErrNone;

#ifdef MSDC_MULTITHREADED
    // check for deferred errors
    if (iWriteDriveThread->DeferredError())
        {
        iWriteDriveThread->ClearDeferredError();
        iDeferredSenseInfo.SetSense(TSenseInfo::EMediumError);
        return NULL;
        }

#endif

    CMassStorageDrive* drive= iDriveManager.Drive(aLun, err);

    if (err !=KErrNone || drive == NULL)
        {
        OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_GETCHECKDRIVE1, "No drive available");
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::ELuNotSupported);
        return NULL;
        }

    CMassStorageDrive::TMountState mountState = drive->MountState();

    if (mountState == CMassStorageDrive::EDisconnected || mountState == CMassStorageDrive::EConnecting)
        {
        OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_GETCHECKDRIVE2, "Drive disconnected");
        iSenseInfo.SetSense(TSenseInfo::ENotReady,
                            TSenseInfo::EMediaNotPresent);
        return NULL;
        }

    CMassStorageDrive::TDriveState state = drive->CheckDriveState();
    if (state == CMassStorageDrive::EMediaNotPresent || state == CMassStorageDrive::ELocked)
        {
        OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_GETCHECKDRIVE3, "Media not present or locked. state =0x%X", state);
        iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
        return NULL;
        }

    if (drive->IsMediaChanged(ETrue))  //reset "media changed" status
        {
        OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_GETCHECKDRIVE4, "Media was changed");
        // SAM-2 Section 5.9.5 Unit Attention Condition
        iSenseInfo.SetSense(TSenseInfo::EUnitAttention, TSenseInfo::ENotReadyToReadyChange);
        iDriveManager.Connect(aLun);   //publish event to USB app
        return NULL;
        }

    if (mountState == CMassStorageDrive::EDisconnecting)
        {
        OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_GETCHECKDRIVE5, "Drive disconnecting");
        iSenseInfo.SetSense(TSenseInfo::ENotReady,
                            TSenseInfo::EMediaNotPresent);
        return NULL;
        }

    return drive;
    }


/**
Command Parser for the UNIT READY command (0x00)

@param aLun Logic unit number
@return ETrue if successful,
*/
TBool CScsiProtocol::HandleUnitReady(TUint aLun)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_TESTUNITREADY, ">>> TEST UNIT READY");
#ifdef MSDC_MULTITHREADED
    iWriteDriveThread->WaitForWriteEmpty();
#endif
    return GetCheckDrive(aLun) ? (TBool)ETrue : (TBool)EFalse;
    }


/**
Command Parser for the REQUEST SENSE command (0x03)

@return ETrue if successful,
*/
TBool CScsiProtocol::HandleRequestSense(TPtrC8& aData)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_REQUESTSENSE, ">>> REQUEST SENSE");
    TUint length = aData[5];
    OstTrace1(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_REQUESTSENSE1, "    length = %d", length);

    TPtr8 writeBuf(NULL, 0);
    iTransport->GetCommandBufPtr(writeBuf, KRequestSenseCommandLength);
    writeBuf.FillZ(KRequestSenseCommandLength);

    TSenseInfo* senseInfo;
#ifdef MSDC_MULTITHREADED
    if (!iDeferredSenseInfo.SenseOk())
        {
        writeBuf[00] = 0x71; //(deferred errors)
        senseInfo = &iDeferredSenseInfo;
        }
    else
        {
        writeBuf[00] = 0x70; //(current errors)
        senseInfo = &iSenseInfo;
        }
#else
    senseInfo = &iSenseInfo;
    writeBuf[00] = 0x70; //(current errors)
#endif

    writeBuf[02] = static_cast<TUint8>(senseInfo->iSenseCode & 0x0F);

    writeBuf[12] = senseInfo->iAdditional;
    writeBuf[13] = senseInfo->iQualifier;
    if (length<18 && length >=8)
        {
        writeBuf.SetLength(length);  //length of response code data
        writeBuf[07] = TUint8(length - 8);  //additional sence length
        }
    else if (length >= KRequestSenseCommandLength)
        {
        writeBuf[07] = KRequestSenseCommandLength - 8;  // we have max 18 byte to send
        }

    OstTraceExt4(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_REQUESTSENSE2,
             "    Response=0x%x Sense=0x%x, Additional=0x%x, Qualifier=0x%x",
             (TUint)writeBuf[0], (TUint)writeBuf[02], (TUint)writeBuf[12], (TUint)writeBuf[13]);

    TPtrC8 writeBuf1 = writeBuf.Left(length);

    iTransport->SetupWriteData(writeBuf1);

    // clear the sense info
    iSenseInfo.SetSense(TSenseInfo::ENoSense);

#ifdef MSDC_MULTITHREADED
    iDeferredSenseInfo.SetSense(TSenseInfo::ENoSense);
#endif

    return ETrue;
    }


/**
Command Parser for the INQUIRY command (0x12)

@param aLun Logic unit number
@return ETrue if successful,
*/
TBool CScsiProtocol::HandleInquiry(TPtrC8& aData, TUint  aLun )
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_INQUIRY, ">>> INQUIRY");
    TBool cmdDt = aData[2] & 0x2;
    TBool evpd  = aData[2] & 0x1;
    TUint8 page = aData[3];
    if (cmdDt || evpd || page || aLun >= KUsbMsMaxDrives)
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    TPtr8 writeBuf(NULL, 0);
    iTransport->GetCommandBufPtr(writeBuf, KInquiryCommandLength);
    writeBuf.FillZ(KInquiryCommandLength);

    writeBuf[1] = 0x80; // MSB: RMB : Removable
    writeBuf[3] = 0x02; // AERC, TrmTsk, NormACA, Response Data Format
    writeBuf[4] = 0x1F; // Additional Length

    TPtr8 vendorId(&writeBuf[8], 8, 8);     // Vendor ID (Vendor Specific/Logged by T10)
    vendorId.Fill(' ', 8);
    vendorId.Copy(iConfig.iVendorId);

    TPtr8 productId(&writeBuf[16], 16, 16); // Product ID (Vendor Specific)
    productId.Fill(' ', 16);
    productId.Copy(iConfig.iProductId);

    TPtr8 productRev(&writeBuf[32], 4, 4);      // Product Revision Level (Vendor Specific)
    productRev.Fill(' ', 4);
    productRev.Copy(iConfig.iProductRev);

    OstTraceData(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_INQUIRY1, "Vendor ID %s", vendorId.Ptr(), vendorId.Length());
    OstTraceData(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_INQUIRY2, "Product ID %s", productId.Ptr(), productId.Length());
    OstTraceData(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_INQUIRY3, "Product Rev %s", productRev.Ptr(), productRev.Length());

    TUint length = aData[5];

    TPtrC8 writeBuf1 = writeBuf.Left(length);
    iTransport->SetupWriteData(writeBuf1);

    iSenseInfo.SetSense(TSenseInfo::ENoSense);
    return ETrue;
    }


/**
 Command Parser for the START STOP UNIT command (0x1B)

 @param aData command data (started form position 1)
 @param aLun Logic unit number
 @return ETrue if successful, TFalse otherwise
 */
TBool CScsiProtocol::HandleStartStopUnit(TPtrC8& aData, TUint aLun)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_STARTSTOPUNIT, ">>> START STOP UNIT");
    const TUint8 KStartMask = 0x01;
    const TUint8 KImmedMask = 0x01;
    const TUint8 KLoejMask = 0x02;

    TBool immed = aData[2] & KImmedMask ? (TBool)ETrue : (TBool)EFalse;
    TBool start = aData[5] & KStartMask ? (TBool)ETrue : (TBool)EFalse;
    TBool loej = aData[5] & KLoejMask ? (TBool)ETrue : (TBool)EFalse;

    OstTrace1(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_STARTSTOPUNIT1, "    IMMED = %d", immed);
    OstTrace1(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_STARTSTOPUNIT2, "    START = %d", start);
    OstTrace1(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_STARTSTOPUNIT3, "    LOEJ = %d", loej);

    TInt err(KErrNone);
    if (loej)
        {
        if(start)   //Start unit
            {
            err = iDriveManager.Connect(aLun);

#ifdef USB_TRANSFER_PUBLISHER
            iBytesRead[aLun] = 0;
            iBytesWritten[aLun] = 0;
#endif
            // publish the initial values
            iWriteTransferPublisher->DoPublishDataTransferredEvent();
            iReadTransferPublisher->DoPublishDataTransferredEvent();
            }
        else        //Stop unit
            {
            iDriveManager.SetCritical(aLun, EFalse);
            err = iDriveManager.Disconnect(aLun);
            }
        }

    if (err !=KErrNone)  //actually we have error here only if the LUN is incorrect
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::ELuNotSupported);
        return EFalse;
        }
    if (immed)
        {
        return ETrue;
        }

    CMassStorageDrive* drive= iDriveManager.Drive(aLun, err);

    if (err !=KErrNone || drive == NULL)
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::ELuNotSupported);
        return EFalse;
        }

    TInt  timeLeft (20);   // 1 sec timeout
    CMassStorageDrive::TMountState mountState;

    do
        {
        User::After(1000 * 50);     // 50 mSec
        --timeLeft;
        mountState = drive->MountState();

        if ((!start && mountState != CMassStorageDrive::EConnected)
             ||
             (start &&
                (mountState == CMassStorageDrive::EDisconnecting ||
                mountState == CMassStorageDrive::EConnected))
            )
            {
            return ETrue;
            }
        } while (timeLeft>0);

    //timeout happend
    iSenseInfo.SetSense(TSenseInfo::ENotReady,
                        TSenseInfo::EAscLogicalUnitDoesNotRespondToSelection);
    return EFalse;
    }


/**
Command Parser for the PREVENT/ALLOW MEDIA REMOVAL command (0x1E)

@param aData command data (started form position 1)
@param aLun Logic unit number
@return ETrue if successful.
*/
TBool CScsiProtocol::HandlePreventMediaRemoval(TPtrC8& aData, TUint aLun)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_PREVENTMEDIAREMOVAL, ">>> PREVENT MEDIA REMOVAL");
    CMassStorageDrive* drive=GetCheckDrive(aLun);

    if (drive == NULL)
        {
        return EFalse;
        }

    TInt prevent = aData[5] & 0x01;
    OstTrace1(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_PREVENTMEDIAREMOVAL1, "    prevent = %d", prevent);
    iDriveManager.SetCritical(aLun, prevent);
    return ETrue;
    }


/** Cancel active state, Invoked by transnport when it stops */
TInt CScsiProtocol::Cancel()
    {
    iDriveManager.SetCritical(CDriveManager::KAllLuns, EFalse);
    return KErrNone;
    }


TBool CScsiProtocol::HandleReadFormatCapacities(TUint aLun)
/**
 * Command Parser for the READ FORMAT CAPACITIES command (0x23)
 *
 * @return ETrue if successful, else a standard Symbian OS error code.
 */
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_READFORMATCAPACITIES, ">>> READ FORMAT CAPACITIES");
    CMassStorageDrive* drive=GetCheckDrive(aLun);

    if (drive == NULL)
        {
        return EFalse;
        }

    TLocalDriveCapsV4 driveInfo;

    TInt err = drive->Caps(driveInfo);

    if(err != KErrNone)
        {
        OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_HANDLEREADFORMATCAPACITIES, "Can't obtain drive Caps. Err=%d", err);
        iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
        return EFalse;
        }

    TInt64 driveBlocks = (driveInfo.iDriveAtt & KDriveAttLogicallyRemovable) ? driveInfo.iSize : driveInfo.MediaSizeInBytes();
    driveBlocks /= MAKE_TINT64(0, KDefaultBlockSize);

    TPtr8 writeBuf(NULL, 0);
    iTransport->GetCommandBufPtr(writeBuf, KReadFormatCapacitiesCommandLength);
    writeBuf.FillZ(KReadFormatCapacitiesCommandLength);

    writeBuf[3] = 0x08; // Capacity List Length

    TUint32 numBlocks = I64LOW(driveBlocks);

    writeBuf[4] = static_cast<TUint8>((numBlocks & 0xFF000000) >> 24);  // Number of blocks
    writeBuf[5] = static_cast<TUint8>((numBlocks & 0x00FF0000) >> 16);  //
    writeBuf[6] = static_cast<TUint8>((numBlocks & 0x0000FF00) >> 8);   //
    writeBuf[7] = static_cast<TUint8>((numBlocks & 0x000000FF));        //

    writeBuf[8] = 0x02; // Formatted size

    writeBuf[9]  = 0x00;    // 512 Byte Blocks
    writeBuf[10] = 0x02;    //
    writeBuf[11] = 0x00;    //

    TPtrC8 writeBuf1 = writeBuf;

    iTransport->SetupWriteData(writeBuf1);

    return ETrue;
    }


/**
Command Parser for the READ CAPACITY(10) command (0x25)

@param aData command data (started form position 1)
@param aLun Logic unit number
@return ETrue if successful.
*/
TBool CScsiProtocol::HandleReadCapacity(TPtrC8& aData, TUint aLun)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_READCAPACITY, ">>> READ CAPACITY");
    CMassStorageDrive* drive=GetCheckDrive(aLun);

    if (drive == NULL)
        {
        return EFalse;
        }

    TInt pmi = aData[9] & 0x01;
    TInt lba = aData[3] | aData[4] | aData[5] | aData[6];

    if (pmi || lba)   //do not support partial medium indicator
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    TLocalDriveCapsV4 driveInfo;

    TInt err = drive->Caps(driveInfo);

    if(err != KErrNone)
        {
        OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_HANDLEREADCAPACITY1, "ERROR: Can't obtain drive Caps Err=%d", err);
        iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
        return EFalse;
        }

    TInt64 driveBlocks = 0;
    if (driveInfo.iDriveAtt & KDriveAttLogicallyRemovable)
        {
        // Partition Access only
        driveBlocks = driveInfo.iSize / MAKE_TINT64(0, KDefaultBlockSize);
        }
    else
        {
        // whole Media Access
        driveBlocks = driveInfo.MediaSizeInBytes() / MAKE_TINT64(0, KDefaultBlockSize) - 1;
        }


    TPtr8 writeBuf(NULL, 0);
    iTransport->GetCommandBufPtr(writeBuf, KReadCapacityCommandLength);
    writeBuf.FillZ(KReadCapacityCommandLength);

    if (I64HIGH(driveBlocks) == 0)
        {
        TUint32 numBlocks = I64LOW(driveBlocks);

        OstTraceExt2(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_HANDLEREADCAPACITY2,
                  "    Block size=0x%x, NumBlocks=0x%x",
                  KDefaultBlockSize, numBlocks);
        writeBuf[0] = static_cast<TUint8>((numBlocks & 0xFF000000) >> 24);  // Number of blocks
        writeBuf[1] = static_cast<TUint8>((numBlocks & 0x00FF0000) >> 16);
        writeBuf[2] = static_cast<TUint8>((numBlocks & 0x0000FF00) >> 8);
        writeBuf[3] = static_cast<TUint8>((numBlocks & 0x000000FF));
        }
    else
        {
        writeBuf[0] = writeBuf[1] = writeBuf[2] = writeBuf[3] = 0xFF;  // indicate that size more then )0xFFFFFFFF
        }

    writeBuf[4] = static_cast<TUint8>((KDefaultBlockSize & 0xFF000000) >> 24);  // Block Size
    writeBuf[5] = static_cast<TUint8>((KDefaultBlockSize & 0x00FF0000) >> 16);
    writeBuf[6] = static_cast<TUint8>((KDefaultBlockSize & 0x0000FF00) >> 8);
    writeBuf[7] = static_cast<TUint8>((KDefaultBlockSize & 0x000000FF));

    TPtrC8 writeBuf1 = writeBuf;
    iTransport->SetupWriteData(writeBuf1);

    return KErrNone;
    }


/**
Command Parser for the READ10 command (0x28)

@param aData command data (started form position 1)
@param aLun Logic unit number
@return ETrue if successful.
*/
TBool CScsiProtocol::HandleRead10(TPtrC8& aData, TUint aLun)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_READ10, ">>> READ(10)");
    CMassStorageDrive* drive = GetCheckDrive(aLun);
    if (drive == NULL)
        {
        return EFalse;
        }
    TInt rdProtect = aData[2] >> 5;
    if (rdProtect)
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    const TUint32 lba = LBA(aData);
    const TUint32 len = LEN(aData);

    OstTraceExt2(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_HANDLEREAD10_1,
              "    LBA = 0x%x Transfer Len = 0x%x", lba, len);

    if (!len)
        {
        return ETrue; // do nothing - this is not an error
        }

    TLocalDriveCapsV4 driveInfo;
    TInt err = drive->Caps(driveInfo);
    if (err != KErrNone)
        {
        OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_HANDLEREAD10_2, "Can't obtain drive Caps. Err=%d", err);
        iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
        return EFalse;
        }

    const TInt64 bOffset = MAKE_TINT64(0, lba) * KDefaultBlockSize;
    const TInt bLength = len * KDefaultBlockSize;
    const TInt64 theEnd = bOffset + MAKE_TINT64(0, bLength);
    const TInt64 mediaSize = (driveInfo.iDriveAtt & KDriveAttLogicallyRemovable) ? driveInfo.iSize : driveInfo.MediaSizeInBytes() ;

    if (theEnd > mediaSize)  //check if media big enough for this request
        {
        OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_HANDLEREAD10_3, "ERROR: Requested size is out of media range");
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::ELbaOutOfRange);
        return EFalse;
        }

#ifdef MSDC_MULTITHREADED
    iWriteDriveThread->WaitForWriteEmpty();

    // check if our buffer can hold requested data
    if (iReadDriveThread->iThreadContext->MaxBufferLength() < bLength)
        {
        OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_HANDLEREAD10_4, "ERROR: Buffer too small");
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    // Optimisation note : If the host is reading from sectors it just wrote to,
    // then we have to force a cache-miss so that the real data is read from the
    // drive. It would be possible to service the read from the write buffers,
    // but as the host is probably trying to verify the write data, we don't do
    // that for now.
    if (!iReadDriveThread->ReadDriveData(drive, bOffset, bLength, iWriteDriveThread->IsRecentlyWritten(bOffset,bLength)))
        {
        iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
        return EFalse;
        }

    iWriteDriveThread->SetCommandWrite10(EFalse);
    TBlockDesc* &desc = iReadDriveThread->iThreadContext->iBuffer.iDescReadPtr;
    TPtrC8 writeBuf1 = desc->iBuf;
#else

    TPtr8 writeBuf(NULL, 0);
    iTransport->GetReadDataBufPtr(writeBuf);
    // check if our buffer can hold requested data
    if (writeBuf.MaxLength() < bLength)
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    err = drive->Read(bOffset, bLength, writeBuf, drive->IsWholeMediaAccess());

    if (err != KErrNone)
        {
        OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_HANDLEREAD10_5, "ERROR: Read failed err=%d", err);
        iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
        return EFalse;
        }

    TPtrC8 writeBuf1 = writeBuf;
#endif // MSDC_MULTITHREADED
#ifdef USB_TRANSFER_PUBLISHER
    iBytesRead[aLun] += writeBuf1.Length();
#endif
    iReadTransferPublisher->StartTimer();

    // Set up data write to the host
    iTransport->SetupWriteData(writeBuf1);

    return ETrue;
    }


/**
Command Parser for the WRITE(10) command (0x2A)

@param aData command data (started form position 1)
@param aLun Logic unit number
@return ETrue if successful.
*/
TBool CScsiProtocol::HandleWrite10(TPtrC8& aData, TUint aLun)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_WRITE10, ">>> WRITE(10)");
    CMassStorageDrive* drive = GetCheckDrive(aLun);
    if (drive == NULL)
        {
        return EFalse;
        }
    TInt wrProtect = aData[2] >> 5;
    if (wrProtect)
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    const TUint32 lba = LBA(aData);
    const TUint32 len = LEN(aData);
    OstTraceExt2(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_HANDLEWRITE10_1, "LBA = 0x%x, Transfer Len = 0x%x", lba, len);
    if (!len)
        {
        return ETrue; // do nothing - this is not an error
        }

    TLocalDriveCapsV4 driveInfo;
    TInt err = drive->Caps(driveInfo);
    if (err != KErrNone)
        {
        OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_WRITE10_2, "ERROR: Can't obtain drive Caps Err=%d", err);
        iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
        return EFalse;
        }
    if (driveInfo.iMediaAtt & KMediaAttWriteProtected ||
        driveInfo.iMediaAtt & KMediaAttLocked)
        {
        iSenseInfo.SetSense(TSenseInfo::EDataProtection, TSenseInfo::EWriteProtected);
        return EFalse;
        }

    const TInt64 bOffset = MAKE_TINT64(0, lba) * KDefaultBlockSize;
    iBytesRemain = len * KDefaultBlockSize;
    const TInt64 theEnd = bOffset + MAKE_TINT64(0, iBytesRemain);
    const TInt64 mediaSize = (driveInfo.iDriveAtt & KDriveAttLogicallyRemovable) ? driveInfo.iSize : driveInfo.MediaSizeInBytes() ;

    if (theEnd > mediaSize)  //check if media big enough for this request
        {
        OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_HANDLEWRITE10_3, "Requested size is out of media range");
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::ELbaOutOfRange);
        return EFalse;
        }

#ifdef MSDC_MULTITHREADED
    iWriteDriveThread->SetCommandWrite10(ETrue);
#endif

    // Set up the first request for data from the host - either
    // KMaxBufSize or the entire transfer length, whichever is smallest.
    TUint thisLength = (iBytesRemain > KMaxBufSize) ? KMaxBufSize : iBytesRemain;
    thisLength = (thisLength > iMediaWriteSize) ? iMediaWriteSize : thisLength;

    iOffset = bOffset;
    iLastCommand = EWrite10;
    iLastLun = aLun;

    iWriteTransferPublisher->StartTimer();
    iTransport->SetupReadData(thisLength);

    return ETrue;
    }


/**
Command Parser for the VERIFY(10) command (0x2F)

@param aData command data (started form position 1)
@param aLun Logic unit number
@return ETrue if successful.
*/
TBool CScsiProtocol::HandleVerify10(TPtrC8& aData, TUint aLun)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_VERIFY10, ">>> VERIFY(10)");
    CMassStorageDrive* drive = GetCheckDrive(aLun);
    if (drive == NULL)
        {
        return EFalse;
        }

    TInt vrProtect = aData[2] >> 5;
    if (vrProtect)
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    const TUint32 lba = LBA(aData);
    const TUint32 len = LEN(aData);
    OstTraceExt2(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_VERIFY10_1, "VERIFY(10) : LBA = 0x%x Transfer Len = 0x%x", lba, len);

    TInt bytChk = aData[2] & 0x02;
    if (!len)
        {
        return ETrue; // do nothing - this is not an error
        }

    TLocalDriveCapsV4 driveInfo;
    TInt err = drive->Caps(driveInfo);
    if (err != KErrNone)
        {
        OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_VERIFY10_2, "ERROR: Can't obtain drive Caps Err=%d", err);
        iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
        return EFalse;
        }

    const TInt64 bOffset = MAKE_TINT64(0, lba) * KDefaultBlockSize;
    const TInt bLength = len * KDefaultBlockSize;
    const TInt64 theEnd = bOffset + MAKE_TINT64(0, bLength);
    const TInt64 mediaSize = (driveInfo.iDriveAtt & KDriveAttLogicallyRemovable) ? driveInfo.iSize : driveInfo.MediaSizeInBytes() ;

    // check if media big enough for this request
    if (theEnd > mediaSize)
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::ELbaOutOfRange);
        return EFalse;
        }

    // check if our buffer can hold requested data
#ifdef MSDC_MULTITHREADED
    if (iWriteDriveThread->iThreadContext->MaxBufferLength() < bLength)
#else
    TPtr8 writeBuf(NULL, 0);
    iTransport->GetReadDataBufPtr(writeBuf);
    if (writeBuf.MaxLength() < bLength)
#endif
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest, TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    if (!bytChk)
        {
        // BYTCHK==0 : Perform a medium verification with no data comparison and not transfer any data from the application client data-out buffer.
        // The device should attempt to read from the specified locations
#ifdef MSDC_MULTITHREADED
        TPtr8 writeBuf = iWriteDriveThread->iThreadContext->GetReadBuffer(bLength);
#else
        writeBuf.SetLength(bLength);
#endif
        err = drive->Read(bOffset, bLength, writeBuf, drive->IsWholeMediaAccess());
        if (err != KErrNone)
            {
            iSenseInfo.SetSense(TSenseInfo::EMisCompare);
            return EFalse;
            }
        return ETrue;
        }

    // BYTCHK==1 : perform a byte-by-byte comparison of user data read from the medium & user data transferred from the application client data-out buffer.
    // The host sends data in the data-transport phase, and the device should verify that the received data matches what is stored in the device.

    iOffset = bOffset;
    iLastCommand = EVerify10;
    iLastLun = aLun;

    iTransport->SetupReadData(bLength);

    return ETrue;
    }


/**
Called by the transport when the requested data has been read or an error has
occurred during the read.

@param aError Indicate if an error occurs during reading data by transport.
@return KErrAbort if command processing is complete but has failed,
        KErrCompletion if sufficient data is available in the buffer to process
        the transfer immediately, KErrNotReady if insufficient data is
        available in the buffer so the transport should wait for it to arrive,
        KErrNone if command processing is complete and was successful.
*/
TInt CScsiProtocol::ReadComplete(TInt aError)
    {
    OstTrace1(TRACE_SMASSSTORAGE_MEDIA, CSCSIPROTOCOL_READCOMPLETE0, "ReadComplete = 0x%X", aError);
    const TInt64 bOffset = iOffset;
    TUint8 lastCommand = iLastCommand;
    TUint lastLun = iLastLun;

    iOffset = 0;
    iLastCommand = EUndefinedCommand;
    iLastLun = KUndefinedLun;

//  OstTrace1(TRACE_SMASSSTORAGE_MEDIA, CSCSIPROTOCOL_READCOMPLETE1, "lastCommand = d", lastCommand);

    if (aError != KErrNone ||
        lastCommand == EUndefinedCommand ||
        lastLun == KUndefinedLun)
        {
        iSenseInfo.SetSense(TSenseInfo::EAbortedCommand);
        return KErrAbort;
        }

    CMassStorageDrive* drive = GetCheckDrive(lastLun);
    if (drive == NULL)
        {
        return KErrAbort;
        }

    if (lastCommand == EWrite10)
        {
        TPtrC8 writeBuf(NULL, 0);
        iTransport->GetWriteDataBufPtr(writeBuf);

#ifdef USB_TRANSFER_PUBLISHER
    iBytesWritten[lastLun] += writeBuf.Length();
#endif

#ifdef MSDC_MULTITHREADED
        TInt err = iWriteDriveThread->WriteDriveData(drive, bOffset, writeBuf, ProcessWriteComplete, this);

        if (err != KErrNone)
            {
            iDeferredSenseInfo.SetSense(TSenseInfo::EMediumError);
            }

        TUint thisLength = iWriteDriveThread->WriteBufferLength();
#else
        OstTrace1(TRACE_SMASSSTORAGE_MEDIA, CSCSIPROTOCOL_READCOMPLETE2, "SCSI: writing 0x%x bytes", writeBuf.Length());
        TInt err = drive->Write(bOffset, writeBuf, drive->IsWholeMediaAccess());
        if (err != KErrNone)
            {
            OstTrace1(TRACE_SMASSSTORAGE_MEDIA, CSCSIPROTOCOL_READCOMPLETE3, "Error after write = 0x%x", err);
            iSenseInfo.SetSense(TSenseInfo::EAbortedCommand);
            return KErrAbort;
            }

        TUint thisLength = writeBuf.Length();
#endif // MSDC_MULTITHREADED
        iOffset = bOffset + MAKE_TINT64(0, thisLength);
        iBytesRemain -= thisLength;
        if ((TInt)iBytesRemain > 0)
            {
            // More data is expected - set up another request to read from the host
            iLastCommand = EWrite10;
            iLastLun = lastLun;

            TUint minLength = (iBytesRemain < iMediaWriteSize) ? iBytesRemain : iMediaWriteSize;
            TUint bytesAvail = iTransport->BytesAvailable() & ~(KDefaultBlockSize-1);

            TBool wait = EFalse;
            thisLength = bytesAvail ? bytesAvail : minLength;
            if (thisLength < minLength)
                {
                // Not enough data is available at the transport to satisfy the request,
                // so return KErrNotReady to indicate that the transport should wait.
                thisLength = minLength;
                wait = ETrue;
                }

            thisLength = (thisLength > KMaxBufSize) ? KMaxBufSize : thisLength;

            iTransport->SetupReadData(thisLength);

            return wait ? KErrNotReady : KErrCompletion;
            }
        }
    else if (lastCommand == EVerify10)
        {
        HBufC8* hostData = NULL;
        TPtrC8 writeBuf(NULL, 0);
        iTransport->GetWriteDataBufPtr(writeBuf);
#ifdef MSDC_MULTITHREADED
        TRAPD(err, hostData = HBufC8::NewL(writeBuf.Length()));
#else
        TRAPD(err, hostData = HBufC8::NewL(writeBuf.Length()));
#endif
        if (err != KErrNone || hostData == NULL)
            {
            iSenseInfo.SetSense(TSenseInfo::EAbortedCommand, TSenseInfo::EInsufficientRes);
            return KErrAbort;
            }

#ifdef MSDC_MULTITHREADED
        // copy the data
        *hostData = writeBuf;
        TPtr8 readBuf = iWriteDriveThread->iThreadContext->GetReadBuffer();
        err = drive->Read(bOffset, writeBuf.Length(), readBuf, drive->IsWholeMediaAccess());
        if (err == KErrNone)
            {
            err = (hostData->Compare(readBuf) == 0) ? KErrNone : KErrCorrupt;
            }
#else
        *hostData = writeBuf;
        TPtr8 readBuf((TUint8*) writeBuf.Ptr(), writeBuf.Length());
        err = drive->Read(bOffset, writeBuf.Length(), readBuf, drive->IsWholeMediaAccess());
        if (err == KErrNone)
            {
            err = (hostData->Compare(readBuf) == 0) ? KErrNone : KErrCorrupt;
            }
#endif

        if (err != KErrNone)
            {
            iSenseInfo.SetSense(TSenseInfo::EMisCompare);
            }

        delete hostData;
        }
    else // unknown command
        {
        iSenseInfo.SetSense(TSenseInfo::EAbortedCommand);
        }
    return iSenseInfo.SenseOk() ? KErrNone : KErrAbort;
    }


/**
Command Parser for the MODE SENSE(06) command (0x1A)

@return ETrue if successful.
*/
TBool CScsiProtocol::HandleModeSense6(TPtrC8& aData, TUint aLun)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_MODESENSE6, ">>> MODESENSE(06)");
    TInt pageCode = aData[3] & 0x3F;
    TUint8 pageControl= static_cast<TUint8>(aData[3] >>6);

    if (pageCode != KAllPages || pageControl == KChangeableValues)
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest,TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    // reserve 4 bytes for Length, Media type, Device-specific parameter and Block descriptor length
    TPtr8 writeBuf(NULL, 0);
    iTransport->GetCommandBufPtr(writeBuf, KModeSense6CommandLength);
    writeBuf.FillZ(KModeSense6CommandLength);

    if (pageControl != KDefaultValues)
        {
        //check if drive write protected
        CMassStorageDrive* drive=GetCheckDrive(aLun);
        if (drive == NULL)
            {
            OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_HANDLEMODESENSE6_1, "drive == null");
            return EFalse;
            }

        TLocalDriveCapsV4 driveInfo;
        TInt err = drive->Caps(driveInfo);
        if (err != KErrNone)
            {
            OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_MODESENSE6_2, "ERROR: Can't obtain drive Caps Err=%d", err);
            iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
            return EFalse ;
            }

        if (driveInfo.iMediaAtt & KMediaAttWriteProtected)
            {
            writeBuf[2] = 1<<7;  // set SWP bit at the Device Specific parameters
            }
        }

    writeBuf[0]=3;  //Sending only Mode parameter header

    TPtrC8 writeBuf1 = writeBuf;

    iTransport->SetupWriteData(writeBuf1);

    return (iSenseInfo.SenseOk());
    }


/**
Command Parser for the MODE SENSE(10) command (0x5A)

@return ETrue if successful.
*/
TBool CScsiProtocol::HandleModeSense10(TPtrC8& aData, TUint aLun)
    {
    OstTrace0(TRACE_SMASSSTORAGE_SCSI, CSCSIPROTOCOL_MODESENSE10, ">>> MODESENSE(10)");
    TInt pageCode = aData[3] & 0x3F;
    TUint8 pageControl= static_cast<TUint8>(aData[3] >>6);

    if (pageCode != KAllPages || pageControl == KChangeableValues)
        {
        iSenseInfo.SetSense(TSenseInfo::EIllegalRequest,TSenseInfo::EInvalidFieldInCdb);
        return EFalse;
        }

    // reserve 8 bytes for Length, Media type, Device-specific parameter and Block descriptor length
    TPtr8 writeBuf(NULL, 0);
    iTransport->GetCommandBufPtr(writeBuf, KModeSense10CommandLength);
    writeBuf.FillZ(KModeSense10CommandLength);

    if (pageControl != KDefaultValues)
        {
        //check if drive write protected
        CMassStorageDrive* drive=GetCheckDrive(aLun);
        if (drive == NULL)
            {
            OstTrace0(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_HANDLEMODESENSE10_1, "drive == null");
            return EFalse;
            }

        TLocalDriveCapsV4 driveInfo;
        TInt err = drive->Caps(driveInfo);
        if (err != KErrNone)
            {
            OstTrace1(TRACE_SMASSSTORAGE, CSCSIPROTOCOL_MODESENSE10_1, "ERROR: Can't obtain drive Caps Err=%d", err);
            iSenseInfo.SetSense(TSenseInfo::ENotReady, TSenseInfo::EMediaNotPresent);
            return EFalse ;
            }

        if (driveInfo.iMediaAtt & KMediaAttWriteProtected)
            {
            writeBuf[3] = 1<<7;  // set SWP bit at the Device Specific parameters
            }
        }

    writeBuf[1]=6;  //Sending only Mode parameter header

    TPtrC8 writeBuf1 = writeBuf;

    iTransport->SetupWriteData(writeBuf1);

    return (iSenseInfo.SenseOk());
    }