summaryrefslogtreecommitdiff
path: root/drivers/ata
diff options
context:
space:
mode:
authorTejun Heo <tj@kernel.org>2010-01-11 11:14:44 +0900
committerGreg Kroah-Hartman <gregkh@suse.de>2010-02-09 04:50:57 -0800
commitdce6a09aaf62aff73b8123e9bb8ad2247b355848 (patch)
tree5ff55871adf47c20703727dd7700153d09623718 /drivers/ata
parent42f7e233e4afae9d327f24c73379920adc905f95 (diff)
libata: retry link resume if necessary
commit 5040ab67a2c6d5710ba497dc52a8f7035729d7b0 upstream. Interestingly, when SIDPR is used in ata_piix, writes to DET in SControl sometimes get ignored leading to detection failure. Update sata_link_resume() such that it reads back SControl after clearing DET and retry if it's not clear. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: fengxiangjun <fengxiangjun@neusoft.com> Reported-by: Jim Faulkner <jfaulkne@ccs.neu.edu> Signed-off-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libata-core.c38
1 files changed, 31 insertions, 7 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index dc72690ed5db..91fed3c93d66 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3790,21 +3790,45 @@ int sata_link_debounce(struct ata_link *link, const unsigned long *params,
int sata_link_resume(struct ata_link *link, const unsigned long *params,
unsigned long deadline)
{
+ int tries = ATA_LINK_RESUME_TRIES;
u32 scontrol, serror;
int rc;
if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
return rc;
- scontrol = (scontrol & 0x0f0) | 0x300;
+ /*
+ * Writes to SControl sometimes get ignored under certain
+ * controllers (ata_piix SIDPR). Make sure DET actually is
+ * cleared.
+ */
+ do {
+ scontrol = (scontrol & 0x0f0) | 0x300;
+ if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
+ return rc;
+ /*
+ * Some PHYs react badly if SStatus is pounded
+ * immediately after resuming. Delay 200ms before
+ * debouncing.
+ */
+ msleep(200);
- if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
- return rc;
+ /* is SControl restored correctly? */
+ if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
+ return rc;
+ } while ((scontrol & 0xf0f) != 0x300 && --tries);
- /* Some PHYs react badly if SStatus is pounded immediately
- * after resuming. Delay 200ms before debouncing.
- */
- msleep(200);
+ if ((scontrol & 0xf0f) != 0x300) {
+ ata_link_printk(link, KERN_ERR,
+ "failed to resume link (SControl %X)\n",
+ scontrol);
+ return 0;
+ }
+
+ if (tries < ATA_LINK_RESUME_TRIES)
+ ata_link_printk(link, KERN_WARNING,
+ "link resume succeeded after %d retries\n",
+ ATA_LINK_RESUME_TRIES - tries);
if ((rc = sata_link_debounce(link, params, deadline)))
return rc;