[SCSI] Reduce polling in sd.c

If a drive reports that no media is present, there's no point in
continuing to ask it about media status.  This patch (as696) cuts the
TUR polling short as soon as the drive reports no media instead of
going a full 3 iterations.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This commit is contained in:
Alan Stern 2006-10-11 16:48:28 -04:00 committed by James Bottomley
parent 3e082a910d
commit b4d38e38e6

View file

@ -1051,6 +1051,14 @@ sd_spinup_disk(struct scsi_disk *sdkp, char *diskname)
&sshdr, SD_TIMEOUT,
SD_MAX_RETRIES);
/*
* If the drive has indicated to us that it
* doesn't have any media in it, don't bother
* with any more polling.
*/
if (media_not_present(sdkp, &sshdr))
return;
if (the_result)
sense_valid = scsi_sense_valid(&sshdr);
retries++;
@ -1059,14 +1067,6 @@ sd_spinup_disk(struct scsi_disk *sdkp, char *diskname)
((driver_byte(the_result) & DRIVER_SENSE) &&
sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
/*
* If the drive has indicated to us that it doesn't have
* any media in it, don't bother with any of the rest of
* this crap.
*/
if (media_not_present(sdkp, &sshdr))
return;
if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
/* no sense, TUR either succeeded or failed
* with a status error */