From d7fbee050753e153622b5d41bc8bd1cb19cda9b9 Mon Sep 17 00:00:00 2001
From: Tejun Heo <htejun@gmail.com>
Date: Sun, 2 Sep 2007 23:24:48 +0900
Subject: [PATCH] libata: assume ATA_DEV_ATA on diagnostic failure
Certain device which reports diagnostic failure also reports invalid
device signature. Assume ATA_DEV_ATA on diagnostic failure if reset
indicates device presence.
This is fix for bugzilla bug 8784.
http://bugzilla.kernel.org/show_bug.cgi?id=8784
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Edward Amsden <amsden_linux@earthlink.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
---
drivers/ata/libata-core.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index ea8c07b04f29..2116f2794580 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -751,10 +751,20 @@ unsigned int ata_dev_try_classify(struct ata_device *dev, int present,
/* determine if device is ATA or ATAPI */
class = ata_dev_classify(&tf);
- if (class == ATA_DEV_UNKNOWN)
- return ATA_DEV_NONE;
- if ((class == ATA_DEV_ATA) && (ata_chk_status(ap) == 0))
- return ATA_DEV_NONE;
+ if (class == ATA_DEV_UNKNOWN) {
+ /* If the device failed diagnostic, it's likely to
+ * have reported incorrect device signature too.
+ * Assume ATA device if the device seems present but
+ * device signature is invalid with diagnostic
+ * failure.
+ */
+ if (present && (dev->horkage & ATA_HORKAGE_DIAGNOSTIC))
+ class = ATA_DEV_ATA;
+ else
+ class = ATA_DEV_NONE;
+ } else if ((class == ATA_DEV_ATA) && (ata_chk_status(ap) == 0))
+ class = ATA_DEV_NONE;
+
return class;
}