diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2005-07-12 10:45:17 -0400 |
|---|---|---|
| committer | James Bottomley <jejb@mulgrave.(none)> | 2005-09-06 17:21:53 -0500 |
| commit | 4451e472627881e3e2240b224f127c99be500f91 (patch) | |
| tree | 71dfcf330e5dc1faec9c7a54b235d700fc9df68d /drivers/scsi/sd.c | |
| parent | e47373ec1c9aab9ee134f4e2b8249957e9f4c7ef (diff) | |
| download | lwn-4451e472627881e3e2240b224f127c99be500f91.tar.gz lwn-4451e472627881e3e2240b224f127c99be500f91.zip | |
[SCSI] sd: pause in sd_spinup_disk for slow USB devices
This patch adds a delay tailored for USB flash devices that are slow to
initialize their firmware. The symptom is a repeated Unit Attention with
ASC=0x28 (Not Ready to Ready transition). The patch will wait for up to 5
seconds for such devices to become ready. Normal devices won't send the
repeated Unit Attention sense key and hence won't trigger the patch.
This fixes a problem with James Roberts-Thomson's USB device, and I've
seen several reports of other devices exhibiting the same symptoms --
presumably they will be helped as well.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/sd.c')
| -rw-r--r-- | drivers/scsi/sd.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 0410e1bf109a..41ba0809f791 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -984,7 +984,7 @@ static void sd_spinup_disk(struct scsi_disk *sdkp, char *diskname, struct scsi_request *SRpnt, unsigned char *buffer) { unsigned char cmd[10]; - unsigned long spintime_value = 0; + unsigned long spintime_expire = 0; int retries, spintime; unsigned int the_result; struct scsi_sense_hdr sshdr; @@ -1071,12 +1071,27 @@ sd_spinup_disk(struct scsi_disk *sdkp, char *diskname, scsi_wait_req(SRpnt, (void *)cmd, (void *) buffer, 0/*512*/, SD_TIMEOUT, SD_MAX_RETRIES); - spintime_value = jiffies; + spintime_expire = jiffies + 100 * HZ; + spintime = 1; } - spintime = 1; /* Wait 1 second for next try */ msleep(1000); printk("."); + + /* + * Wait for USB flash devices with slow firmware. + * Yes, this sense key/ASC combination shouldn't + * occur here. It's characteristic of these devices. + */ + } else if (sense_valid && + sshdr.sense_key == UNIT_ATTENTION && + sshdr.asc == 0x28) { + if (!spintime) { + spintime_expire = jiffies + 5 * HZ; + spintime = 1; + } + /* Wait 1 second for next try */ + msleep(1000); } else { /* we don't understand the sense code, so it's * probably pointless to loop */ @@ -1088,8 +1103,7 @@ sd_spinup_disk(struct scsi_disk *sdkp, char *diskname, break; } - } while (spintime && - time_after(spintime_value + 100 * HZ, jiffies)); + } while (spintime && time_before_eq(jiffies, spintime_expire)); if (spintime) { if (scsi_status_is_good(the_result)) |