On 12/25/2009 10:35 AM, fengxiangjun wrote:
>> Hmmm... SControl DET hasn't been cleared. Does the attached patch
>> make any difference?
>
> After 5 successful reboots, I think the patch does fix the problem.
> Thank you very much.
Can you please try this one? Retry logic was wrong in the original
patch. With this patch, you should see one "link resume succeeded
after %d retries" message when the original kernel would have failed
probe. Can you please test this patch and post boot log with such
message?
Thanks.
--
tejun
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 22ff51b..40940dd 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3790,21 +3790,40 @@ 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;
+ 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;
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 6a9c4dd..7311225 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -354,6 +354,9 @@ enum {
/* max tries if error condition is still set after ->error_handler */
ATA_EH_MAX_TRIES = 5,
+ /* sometimes resuming a link requires several retries */
+ ATA_LINK_RESUME_TRIES = 5,
+
/* how hard are we gonna try to probe/recover devices */
ATA_PROBE_MAX_TRIES = 3,
ATA_EH_DEV_TRIES = 3,
