libata: limit post SRST nsect/lbal wait to ~100ms

After SRST, libata used to wait for nsect/lbal to be set to 1/1 for
the slave device.  However, some ATAPI devices don't set nsect/lbal
after SRST and the wait itself isn't too useful as we're gonna wait
for !BSY right after that anyway.

Before reset-seq update, nsect/lbal wait failure used to be ignored
and caused 30sec delay during detection.  After reset-seq, all
timeouts are considered error conditions making libata fail to detect
such ATAPI devices.

This patch limits nsect/lbal wait to around 100ms.  This should give
acceptable behavior to such ATAPI devices while not disturbing the
heavily used code path too much.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Tejun Heo 2007-06-10 14:26:20 +09:00 committed by Jeff Garzik
parent 5acd50f641
commit e141d999b6

View file

@ -3061,22 +3061,28 @@ static int ata_bus_post_reset(struct ata_port *ap, unsigned int devmask,
}
}
/* if device 1 was found in ata_devchk, wait for
* register access, then wait for BSY to clear
/* if device 1 was found in ata_devchk, wait for register
* access briefly, then wait for BSY to clear.
*/
while (dev1) {
u8 nsect, lbal;
if (dev1) {
int i;
ap->ops->dev_select(ap, 1);
nsect = ioread8(ioaddr->nsect_addr);
lbal = ioread8(ioaddr->lbal_addr);
if ((nsect == 1) && (lbal == 1))
break;
if (time_after(jiffies, deadline))
return -EBUSY;
msleep(50); /* give drive a breather */
}
if (dev1) {
/* Wait for register access. Some ATAPI devices fail
* to set nsect/lbal after reset, so don't waste too
* much time on it. We're gonna wait for !BSY anyway.
*/
for (i = 0; i < 2; i++) {
u8 nsect, lbal;
nsect = ioread8(ioaddr->nsect_addr);
lbal = ioread8(ioaddr->lbal_addr);
if ((nsect == 1) && (lbal == 1))
break;
msleep(50); /* give drive a breather */
}
rc = ata_wait_ready(ap, deadline);
if (rc) {
if (rc != -ENODEV)