libata: improve EH internal command timeout handling

ATA_TMOUT_INTERNAL which was 30secs were used for all internal
commands which is way too long when something goes wrong.  This patch
implements command type based stepped timeouts.  Different command
types can use different timeouts and each command type can use
different timeout values after timeouts.

ie. the initial timeout is set to a value which should cover most of
the cases but not too long so that run away cases don't delay things
too much.  After the first try times out, the second try can use
longer timeout and if that one times out too, it can go for full 30sec
timeout.

IDENTIFYs use 5s - 10s - 30s timeout and all other commands use 5s -
10s timeouts.

This patch significantly cuts down the needed time to handle failure
cases while still allowing libata to work with nut job devices through
retries.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index c5c3b1b516e1..9bef1a84fe3f 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -144,7 +144,7 @@ static int libata_dma_mask = ATA_DMA_MASK_ATA|ATA_DMA_MASK_ATAPI|ATA_DMA_MASK_CF
 module_param_named(dma, libata_dma_mask, int, 0444);
 MODULE_PARM_DESC(dma, "DMA enable/disable (0x1==ATA, 0x2==ATAPI, 0x4==CF)");
 
-static int ata_probe_timeout = ATA_TMOUT_INTERNAL / 1000;
+static int ata_probe_timeout;
 module_param(ata_probe_timeout, int, 0444);
 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
 
@@ -1611,6 +1611,7 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
         struct ata_link *link = dev->link;
         struct ata_port *ap = link->ap;
         u8 command = tf->command;
+        int auto_timeout = 0;
         struct ata_queued_cmd *qc;
         unsigned int tag, preempted_tag;
         u32 preempted_sactive, preempted_qc_active;
@@ -1683,8 +1684,14 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 
         spin_unlock_irqrestore(ap->lock, flags);
 
-        if (!timeout)
-                timeout = ata_probe_timeout * 1000;
+        if (!timeout) {
+                if (ata_probe_timeout)
+                        timeout = ata_probe_timeout * 1000;
+                else {
+                        timeout = ata_internal_cmd_timeout(dev, command);
+                        auto_timeout = 1;
+                }
+        }
 
         rc = wait_for_completion_timeout(&wait, msecs_to_jiffies(timeout));
 
@@ -1760,6 +1767,9 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
 
         spin_unlock_irqrestore(ap->lock, flags);
 
+        if ((err_mask & AC_ERR_TIMEOUT) && auto_timeout)
+                ata_internal_cmd_timed_out(dev, command);
+
         return err_mask;
 }