ide: fix OOPS during ide-cd error recovery

On Tuesday 19 May 2009 20:29:28 Martin Lottermoser wrote:

>   hdc: cdrom_decode_status: error=0x40 <3>{ LastFailedSense=0x04 }
>   ide: failed opcode was: unknown
>   hdc: DMA disabled
>   ------------[ cut here ]------------
>   kernel BUG at drivers/ide/ide-io.c:872!

It is possible for ide-cd to ignore ide_error()'s return value under
some circumstances.  Workaround it in ide_intr() and ide_timer_expiry()
by checking if there is a device/port reset pending currently.

Fixes bug #13345:

	http://bugzilla.kernel.org/show_bug.cgi?id=13345

Reported-by: Martin Lottermoser <Martin.Lottermoser@t-online.de>
Reported-and-tested-by: Modestas Vainius <modestas@vainius.eu>
Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-io.c

@@ -696,7 +696,7 @@ void ide_timer_expiry (unsigned long data)
 		}
 		spin_lock_irq(&hwif->lock);
 		enable_irq(hwif->irq);
-		if (startstop == ide_stopped) {
+		if (startstop == ide_stopped && hwif->polling == 0) {
 			ide_unlock_port(hwif);
 			plug_device = 1;
 		}
@@ -868,7 +868,7 @@ irqreturn_t ide_intr (int irq, void *dev_id)
 	 * same irq as is currently being serviced here, and Linux
 	 * won't allow another of the same (on any CPU) until we return.
 	 */
-	if (startstop == ide_stopped) {
+	if (startstop == ide_stopped && hwif->polling == 0) {
 		BUG_ON(hwif->handler);
 		ide_unlock_port(hwif);
 		plug_device = 1;