Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...

[pandora-kernel.git] / drivers / ata / libata-core.c

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 22ff51b..6728328 100644 (file)
--- 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;