diff options
Diffstat (limited to 'drivers/usb/storage/transport.c')
| -rw-r--r-- | drivers/usb/storage/transport.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c index 9cc30af..1d5438e 100644 --- a/drivers/usb/storage/transport.c +++ b/drivers/usb/storage/transport.c @@ -57,6 +57,9 @@ #include "scsiglue.h" #include "debug.h" +#include <linux/blkdev.h> +#include "../../scsi/sd.h" + /*********************************************************************** * Data transfer routines @@ -511,6 +514,110 @@ int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe, * Transport routines ***********************************************************************/ +/* There are so many devices that report the capacity incorrectly, + * this routine was written to counteract some of the resulting + * problems. + */ +static void last_sector_hacks(struct us_data *us, struct scsi_cmnd *srb) +{ + struct gendisk *disk; + struct scsi_disk *sdkp; + u32 sector; + + /* To Report "Medium Error: Record Not Found */ + static unsigned char record_not_found[18] = { + [0] = 0x70, /* current error */ + [2] = MEDIUM_ERROR, /* = 0x03 */ + [7] = 0x0a, /* additional length */ + [12] = 0x14 /* Record Not Found */ + }; + + /* If last-sector problems can't occur, whether because the + * capacity was already decremented or because the device is + * known to report the correct capacity, then we don't need + * to do anything. + */ + if (!us->use_last_sector_hacks) + return; + + /* Was this command a READ(10) or a WRITE(10)? */ + if (srb->cmnd[0] != READ_10 && srb->cmnd[0] != WRITE_10) + goto done; + + /* Did this command access the last sector? */ + sector = (srb->cmnd[2] << 24) | (srb->cmnd[3] << 16) | + (srb->cmnd[4] << 8) | (srb->cmnd[5]); + disk = srb->request->rq_disk; + if (!disk) + goto done; + sdkp = scsi_disk(disk); + if (!sdkp) + goto done; + if (sector + 1 != sdkp->capacity) + goto done; + + if (srb->result == SAM_STAT_GOOD && scsi_get_resid(srb) == 0) { + + /* The command succeeded. If the capacity is odd + * (i.e., if the sector number is even) then the + * "always-even" heuristic would be wrong for this + * device. Issue a WARN() so that the kerneloops.org + * project will be notified and we will then know to + * mark the device with a CAPACITY_OK flag. Hopefully + * this will occur for only a few devices. + * + * Use the sign of us->last_sector_hacks to tell whether + * the warning has already been issued; we don't need + * more than one warning per device. + */ + if (!(sector & 1) && us->use_last_sector_hacks > 0) { + unsigned vid = le16_to_cpu( + us->pusb_dev->descriptor.idVendor); + unsigned pid = le16_to_cpu( + us->pusb_dev->descriptor.idProduct); + unsigned rev = le16_to_cpu( + us->pusb_dev->descriptor.bcdDevice); + + WARN(1, "%s: Successful last sector success at %u, " + "device %04x:%04x:%04x\n", + sdkp->disk->disk_name, sector, + vid, pid, rev); + us->use_last_sector_hacks = -1; + } + + } else { + /* The command failed. Allow up to 3 retries in case this + * is some normal sort of failure. After that, assume the + * capacity is wrong and we're trying to access the sector + * beyond the end. Replace the result code and sense data + * with values that will cause the SCSI core to fail the + * command immediately, instead of going into an infinite + * (or even just a very long) retry loop. + */ + if (++us->last_sector_retries < 3) + return; + srb->result = SAM_STAT_CHECK_CONDITION; + memcpy(srb->sense_buffer, record_not_found, + sizeof(record_not_found)); + + /* In theory we might want to issue a WARN() here if the + * capacity is even, since it could indicate the device + * has the READ CAPACITY bug _and_ the real capacity is + * odd. But it could also indicate that the device + * simply can't access its last sector, a failure mode + * which is surprisingly common. So no warning. + */ + } + + done: + /* Don't reset the retry counter for TEST UNIT READY commands, + * because they get issued after device resets which might be + * caused by a failed last-sector access. + */ + if (srb->cmnd[0] != TEST_UNIT_READY) + us->last_sector_retries = 0; +} + /* Invoke the transport and basic error-handling/recovery methods * * This is used by the protocol layers to actually send the message to @@ -544,6 +651,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us) /* if the transport provided its own sense data, don't auto-sense */ if (result == USB_STOR_TRANSPORT_NO_SENSE) { srb->result = SAM_STAT_CHECK_CONDITION; + last_sector_hacks(us, srb); return; } @@ -705,6 +813,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us) scsi_bufflen(srb) - scsi_get_resid(srb) < srb->underflow) srb->result = (DID_ERROR << 16) | (SUGGEST_RETRY << 24); + last_sector_hacks(us, srb); return; /* Error and abort processing: try to resynchronize with the device @@ -732,6 +841,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us) us->transport_reset(us); } clear_bit(US_FLIDX_RESETTING, &us->dflags); + last_sector_hacks(us, srb); } /* Stop the current URB transfer */ |