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authorMark Lord <liml@rtr.ca>2009-04-06 15:24:57 -0400
committerJeff Garzik <jgarzik@redhat.com>2009-04-06 20:13:50 -0400
commit2009177329ae565d9e9efd31b399d2f4ed4f0c44 (patch)
treedc68c765e3295802e69a96c52ed0e08f604121cd /drivers/ata/sata_mv.c
parent65ad7fef10b50b6c06d6165fa847e2d3636b0a66 (diff)
sata_mv: workaround errata SATA#26
Workaround for errata SATA#26. Prevents accidently putting a drive to sleep when attempting COMRESET, by ORing 0xf000 with the values written to SCR_CONTROL. Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/sata_mv.c')
-rw-r--r--drivers/ata/sata_mv.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index b0c929d36234..d689fb9ceb96 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -1296,7 +1296,25 @@ static int mv_scr_write(struct ata_link *link, unsigned int sc_reg_in, u32 val)
unsigned int ofs = mv_scr_offset(sc_reg_in);
if (ofs != 0xffffffffU) {
- writelfl(val, mv_ap_base(link->ap) + ofs);
+ void __iomem *addr = mv_ap_base(link->ap) + ofs;
+ if (sc_reg_in == SCR_CONTROL) {
+ /*
+ * Workaround for 88SX60x1 FEr SATA#26:
+ *
+ * COMRESETs have to take care not to accidently
+ * put the drive to sleep when writing SCR_CONTROL.
+ * Setting bits 12..15 prevents this problem.
+ *
+ * So if we see an outbound COMMRESET, set those bits.
+ * Ditto for the followup write that clears the reset.
+ *
+ * The proprietary driver does this for
+ * all chip versions, and so do we.
+ */
+ if ((val & 0xf) == 1 || (readl(addr) & 0xf) == 1)
+ val |= 0xf000;
+ }
+ writelfl(val, addr);
return 0;
} else
return -EINVAL;