Thanks again for the help, but, I could use a little more instruction...
I've figured out how to apply the patch to the source, and compiled
the libata-pmp, and libata-eh modules(/drivers/ata), but, I cannot
figure out what to do from here.
The libata-pmp driver/module does not seem to be loaded on my system
to begin with...maybe this was part of my problem.
On Sat, Oct 8, 2011 at 1:25 PM, Michael Ihrcke <mihrcke@xxxxxxxxx> wrote:
> Thank you...
>
> Will this require a complete kernel recompile?
> Or is there an easier way to include this patch?
>
> I have little to no experience with working with patches at this level.
> I've been doing research on how to use this patch, and I'm close, but, I'm not
> sure if I need to attack compiling a kernel, or if I can somehow just patch
> libata or something like that?
>
> Thank you,
> Mike
>
> On Thu, Oct 6, 2011 at 12:48 AM, Gwendal Grignou <gwendal@xxxxxxxxxx> wrote:
>>
>> I think I know what is going on. One of your disks at least is slow to
>> spinup. Due to a bug/feature in silicon image disk controller and pmp,
>> at bring up we can not issue a SOFT_RESET and wait for the disk to
>> spinup and then continue.
>> That why we set ATA_LFLAG_NO_SRST in sata_pmp_quirks().
>> So what happen is we go into a function that issue identify, but we
>> fail, the disk is not ready [it is spinning up], so we retry.
>> 3 times.
>>
>> From the first hard reset: 12888.470385, to the time you got the final
>> error: 12901.397305 ~ 12.9s
>> In the second case, your controller can send SOFT_RESET and wait for
>> the device to respond.
>> Time for the disk to spinup:
>> 28010.630028 - 27997.097116 ~ 13.5s
>> As you can see, you are borderline with the PMP, but the controller
>> did not "wait" enough in the first case.
>> Given the spinup time varies with drive, age, time since last
>> spin-up..., it may work one day and fail the next.
>> To work around the problem, I have a patch that consist of allowing
>> the silicon image control to send a reset, but if it fails, we spin
>> for a fixed amount of time and retry. This is not very nice, it is a
>> better design to wait for event that waiting a fixed amount of time.
>> You may have to alter ATA_LFLAG_WAIT_SRST to use the first bit available.
>>
>> Can you try with the following patch?
>>
>> Thanks,
>> Gwendal.
>>
>> diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
>> index 228740f..b98b02d 100644
>> --- a/drivers/ata/libata-eh.c
>> +++ b/drivers/ata/libata-eh.c
>> @@ -2798,7 +2798,14 @@ int ata_eh_reset(struct ata_link *link, int classify,
>> sata_scr_read(link, SCR_STATUS, &sstatus))
>> rc = -ERESTART;
>>
>> - if (rc == -ERESTART || try >= max_tries)
>> + if (try >= max_tries)
>> + goto out;
>> +
>> + /* Some PMP will not serve SRST until the disk is spunup,
>> + * if the controller can not wait for the PMP to acknowledge the frame,
>> + * wait here */
>> + if (rc == -ERESTART &&
>> + !((lflags & ATA_LFLAG_WAIT_SRST) && (reset == softreset)))
>> goto out;
>>
>> now = jiffies;
>> @@ -2813,6 +2820,8 @@ int ata_eh_reset(struct ata_link *link, int classify,
>> delta = schedule_timeout_uninterruptible(delta);
>> }
>>
>> + if (rc == -ERESTART)
>> + goto out;
>> if (try == max_tries - 1) {
>> sata_down_spd_limit(link, 0);
>> if (slave)
>> diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
>> index 00305f4..d21ad7d 100644
>> --- a/drivers/ata/libata-pmp.c
>> +++ b/drivers/ata/libata-pmp.c
>> @@ -325,13 +351,11 @@ static void sata_pmp_quirks(struct ata_port *ap)
>> if (vendor == 0x1095 && devid == 0x3726) {
>> /* sil3726 quirks */
>> ata_for_each_link(link, ap, EDGE) {
>> - /* Class code report is unreliable and SRST
>> - * times out under certain configurations.
>> - */
>> + /* Class code report is unreliable */
>> + /* PMP does not forward SRST until the drive spins up */
>> if (link->pmp < 5)
>> - link->flags |= ATA_LFLAG_NO_SRST |
>> - ATA_LFLAG_ASSUME_ATA;
>> -
>> + link->flags |= ATA_LFLAG_ASSUME_ATA |
>> + ATA_LFLAG_WAIT_SRST;
>> /* port 5 is for SEMB device and it doesn't like SRST */
>> if (link->pmp == 5)
>> link->flags |= ATA_LFLAG_NO_SRST |
>> diff --git a/include/linux/libata.h b/include/linux/libata.h
>> index b2f2003..3a18caa 100644
>> --- a/include/linux/libata.h
>> +++ b/include/linux/libata.h
>> @@ -172,6 +172,7 @@ enum {
>> ATA_LFLAG_NO_RETRY = (1 << 5), /* don't retry this link */
>> ATA_LFLAG_DISABLED = (1 << 6), /* link is disabled */
>> ATA_LFLAG_SW_ACTIVITY = (1 << 7), /* keep activity stats */
>> + ATA_LFLAG_WAIT_SRST = (1 << 8), /* add delay when SRST fails */
>>
>> /* struct ata_port flags */
>> ATA_FLAG_SLAVE_POSS = (1 << 0), /* host supports slave dev */
>>
>>
>
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