[PATCH v2] libata: skip old error history when counting probe trials

[PATCH v2] libata: skip old error history when counting probe trials

[Lin Ming]

Commit d902747("[libata] Add ATA transport class") introduced
ATA_EFLAG_OLD_ER to mark entries in the error ring as cleared.

But ata_count_probe_trials_cb() didn't check this flag and it still
counts the old error history. So wrong probe trials count is returned
and it causes problem, for example, SATA link speed is slowed down from
3.0Gbps to 1.5Gbps.

Fix it by checking ATA_EFLAG_OLD_ER in ata_count_probe_trials_cb().

Cc: stable <stable@vger.kernel.org> # 2.6.37+
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
---

v2: update logs, specify the summary of commit d902747

 drivers/ata/libata-eh.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index c61316e..d1fbd59 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3501,7 +3501,8 @@ static int ata_count_probe_trials_cb(struct ata_ering_entry *ent, void *void_arg
 	u64 now = get_jiffies_64();
 	int *trials = void_arg;
 
-	if (ent->timestamp < now - min(now, interval))
+	if ((ent->eflags & ATA_EFLAG_OLD_ER) ||
+	    (ent->timestamp < now - min(now, interval)))
 		return -1;
 
 	(*trials)++;
-- 
1.7.9

Re: [PATCH v2] libata: skip old error history when counting probe trials

[Gwendal Grignou]

On Thu, May 3, 2012 at 7:15 AM, Lin Ming <ming.m.lin@intel.com> wrote:
> Commit d902747("[libata] Add ATA transport class") introduced
> ATA_EFLAG_OLD_ER to mark entries in the error ring as cleared.
>
> But ata_count_probe_trials_cb() didn't check this flag and it still
> counts the old error history. So wrong probe trials count is returned
> and it causes problem, for example, SATA link speed is slowed down from
> 3.0Gbps to 1.5Gbps.
>
> Fix it by checking ATA_EFLAG_OLD_ER in ata_count_probe_trials_cb().
>
> Cc: stable <stable@vger.kernel.org> # 2.6.37+
> Signed-off-by: Lin Ming <ming.m.lin@intel.com>
> ---
>
> v2: update logs, specify the summary of commit d902747
>
>  drivers/ata/libata-eh.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
> index c61316e..d1fbd59 100644
> --- a/drivers/ata/libata-eh.c
> +++ b/drivers/ata/libata-eh.c
> @@ -3501,7 +3501,8 @@ static int ata_count_probe_trials_cb(struct ata_ering_entry *ent, void *void_arg
>        u64 now = get_jiffies_64();
>        int *trials = void_arg;
>
> -       if (ent->timestamp < now - min(now, interval))
> +       if ((ent->eflags & ATA_EFLAG_OLD_ER) ||
> +           (ent->timestamp < now - min(now, interval)))
>                return -1;
>
>        (*trials)++;
> --
> 1.7.9
>

Acked-by: Gwendal Grignou <gwendal@google.com>