diff options
| author | Mark Lord <liml@rtr.ca> | 2009-04-06 15:24:57 -0400 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@redhat.com> | 2009-04-06 20:13:50 -0400 |
| commit | 2009177329ae565d9e9efd31b399d2f4ed4f0c44 (patch) | |
| tree | dc68c765e3295802e69a96c52ed0e08f604121cd /drivers/ata/sata_mv.c | |
| parent | 65ad7fef10b50b6c06d6165fa847e2d3636b0a66 (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.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c index b0c929d3623..d689fb9ceb9 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; |