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[SCSI] sd: Use SCSI read/write(16) with > 32-bit LBA drives
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Force large capacity (> 0xFFFFFFFF blocks) drives to use READ/WRITE(16) instead
of READ/WRITE(10). Some(most/all?) USB enclosures do not like READ(10) commands
when a large capacity drive is installed. This issue was reported and discussed
here: http://marc.info/?l=linux-usb&m=135247705222324

Signed-off-by: Jason J. Herne <hernejj@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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hernejj authored and James Bottomley committed Nov 27, 2012
1 parent 0b43344 commit 53ad570
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Showing 2 changed files with 4 additions and 1 deletion.
4 changes: 3 additions & 1 deletion drivers/scsi/sd.c
Original file line number Diff line number Diff line change
Expand Up @@ -1011,7 +1011,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
SCpnt->cmnd[29] = (unsigned char) (this_count >> 16) & 0xff;
SCpnt->cmnd[30] = (unsigned char) (this_count >> 8) & 0xff;
SCpnt->cmnd[31] = (unsigned char) this_count & 0xff;
} else if (block > 0xffffffff) {
} else if (sdp->use_16_for_rw) {
SCpnt->cmnd[0] += READ_16 - READ_6;
SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
Expand Down Expand Up @@ -2203,6 +2203,8 @@ sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
}
}

sdp->use_16_for_rw = (sdkp->capacity > 0xffffffff);

/* Rescale capacity to 512-byte units */
if (sector_size == 4096)
sdkp->capacity <<= 3;
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1 change: 1 addition & 0 deletions include/scsi/scsi_device.h
Original file line number Diff line number Diff line change
Expand Up @@ -137,6 +137,7 @@ struct scsi_device {
unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */
unsigned no_report_opcodes:1; /* no REPORT SUPPORTED OPERATION CODES */
unsigned no_write_same:1; /* no WRITE SAME command */
unsigned use_16_for_rw:1; /* Use read/write(16) over read/write(10) */
unsigned skip_ms_page_8:1; /* do not use MODE SENSE page 0x08 */
unsigned skip_ms_page_3f:1; /* do not use MODE SENSE page 0x3f */
unsigned skip_vpd_pages:1; /* do not read VPD pages */
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