[PATCH] libata: always use polling IDENTIFY

libata switched to IRQ-driven IDENTIFY when IRQ-driven PIO was
introduced.  This has caused a lot of problems including device
misdetection and phantom device.

ATA_FLAG_DETECT_POLLING was added recently to selectively use polling
IDENTIFY on problemetic drivers but many controllers and devices are
affected by this problem and trying to adding ATA_FLAG_DETECT_POLLING
for each such case is diffcult and not very rewarding.

This patch makes libata always use polling IDENTIFY.  This is
consistent with libata's original behavior and drivers/ide's behavior.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 2 insertions, 6 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 883276388207..f8ec3896b793 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1473,16 +1473,12 @@ int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
         }
 
         tf.protocol = ATA_PROT_PIO;
-
-        /* presence detection using polling IDENTIFY? */
-        if (flags & ATA_READID_DETECT)
-                tf.flags |= ATA_TFLAG_POLLING;
+        tf.flags |= ATA_TFLAG_POLLING; /* for polling presence detection */
 
         err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
                                      id, sizeof(id[0]) * ATA_ID_WORDS);
         if (err_mask) {
-                if ((flags & ATA_READID_DETECT) &&
-                    (err_mask & AC_ERR_NODEV_HINT)) {
+                if (err_mask & AC_ERR_NODEV_HINT) {
                         DPRINTK("ata%u.%d: NODEV after polling detection\n",
                                 ap->id, dev->devno);
                         return -ENOENT;