[PATCH] ide: fix error handling for drives which clear the FIFO on error

If the controller FIFO cleared automatically on error we must not try
and drain it as this will hang some chips.

Based in concept on a broken patch from -mm some while back
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/ide/ide-io.c

@@ -505,7 +505,7 @@ static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8
 		}
 	}
 
-	if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ)
+	if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ && hwif->err_stops_fifo == 0)
 		try_to_flush_leftover_data(drive);
 
 	if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))

include/linux/ide.h

@@ -793,6 +793,7 @@ typedef struct hwif_s {
 	unsigned	auto_poll  : 1; /* supports nop auto-poll */
 	unsigned	sg_mapped  : 1;	/* sg_table and sg_nents are ready */
 	unsigned	no_io_32bit : 1; /* 1 = can not do 32-bit IO ops */
+	unsigned	err_stops_fifo : 1; /* 1=data FIFO is cleared by an error */
 
 	struct device	gendev;
 	struct completion gendev_rel_comp; /* To deal with device release() */