> busy. Here are the symptoms of my problem : doing reads from a CDROM
> device intermingled with CDROM_MEDIA_CHANGED ioctls causes long pauses
> during the ioctl. This behavior started in 2.4.10. The ioctl can take a
> very long time to return, especially if reading large chunks.
This patch fixes the problem for my USB CDROM device. Maybe a similar
patch is needed for the IDE case, I haven't looked yet.
In general, who is responsible for unplugging the request queue after
queuing an ioctl command?
--- linux/drivers/scsi/scsi.c.old Thu Nov 29 00:42:16 2001
+++ linux/drivers/scsi/scsi.c Thu Nov 29 00:32:28 2001
@@ -767,14 +767,17 @@
void scsi_wait_req (Scsi_Request * SRpnt, const void *cmnd ,
void *buffer, unsigned bufflen,
int timeout, int retries)
{
+ request_queue_t *q;
DECLARE_COMPLETION(wait);
SRpnt->sr_request.waiting = &wait;
SRpnt->sr_request.rq_status = RQ_SCSI_BUSY;
scsi_do_req (SRpnt, (void *) cmnd,
buffer, bufflen, scsi_wait_done, timeout, retries);
+ q = &SRpnt->sr_device->request_queue;
+ generic_unplug_device(q);
wait_for_completion(&wait);
SRpnt->sr_request.waiting = NULL;
if( SRpnt->sr_command != NULL )
{
-- Peter Österlund petero2@telia.com Sköndalsvägen 35 http://w1.894.telia.com/~u89404340 S-128 66 Sköndal +46 8 942647 Sweden - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/