sata_fsl: Fix wrong Device Error Register usage

When a single device error is detected, the device under the error
is indicated by the error bit set in the DER. There is a one to one
mapping between register bit and devices on Port multiplier(PMP)
i.e. bit 0 represents PMP device 0 and bit 1 represents PMP device
1 etc.

Current implementation treats Device error register value as device
number not set of bits representing multiple device on PMP. It is
changed to consider bit level.

No need to check for each set bit as all command is going to be
aborted.

Signed-off-by: Ashish Kalra <B00888@freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
index beef37134a042ee01a589bcbf691e966ff97bacf..2ddb567f165bca041708afb29434e967f0bd4d25 100644 (file)
--- a/drivers/ata/sata_fsl.c
+++ b/drivers/ata/sata_fsl.c
@@ -1039,12 +1039,15 @@ static void sata_fsl_error_intr(struct ata_port *ap)
 
                /* find out the offending link and qc */
                if (ap->nr_pmp_links) {
+                       unsigned int dev_num;
+
                        dereg = ioread32(hcr_base + DE);
                        iowrite32(dereg, hcr_base + DE);
                        iowrite32(cereg, hcr_base + CE);
 
-                       if (dereg < ap->nr_pmp_links) {
-                               link = &ap->pmp_link[dereg];
+                       dev_num = ffs(dereg) - 1;
+                       if (dev_num < ap->nr_pmp_links && dereg != 0) {
+                               link = &ap->pmp_link[dev_num];
                                ehi = &link->eh_info;
                                qc = ata_qc_from_tag(ap, link->active_tag);
                                /*