Re: 2.6.23-mm1

Jeff Garzik
2007-10-13T17:49:09Z

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Torsten Kaiser wrote:
> On 10/13/07, Torsten Kaiser <just.for.lkml@googlemail.com> wrote:
>> Wait!
>>
>> I think I found the bug: Its a evil interaction between the above
>> patch and the swncq patch that is applied later.
>> The qc_defer patch removes the old ata_scmd_need_defer that was always
>> called for all drivers and substitutes it for ata_std_qc_defer and
>> adds it as aops->qc_defer to all drivers that support NCQ *at that
>> point*.
>> Then the swncq patch adds a new NCQ capable driver, but the nobody
>> added the qc_defer-ops to the ops-structure that is added. So swncq
>> will never defer any commands and the first command that would need to
>> be defered (the SMART commands) blows up, if there is still another
>> command in flight.
>>
>> I will only add the qc_defer and try this...
>
> 3 boots, all worked. So I'm very sure that was the bug, but I will now
> do a little load testing...
>
> The only strange thing about 2.6.23-mm1 is, that it takes ~4 second
> more to boot.

So, you basically applied the attached patch?

Yeah, absence of qc_defer for an NCQ-capable chip would do it.

Jeff

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diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index cf5c85e..240a892 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -554,6 +554,7 @@ static const struct ata_port_operations nv_swncq_ops = {
.bmdma_start = ata_bmdma_start,
.bmdma_stop = ata_bmdma_stop,
.bmdma_status = ata_bmdma_status,
+ .qc_defer = ata_std_qc_defer,
.qc_prep = nv_swncq_qc_prep,
.qc_issue = nv_swncq_qc_issue,
.freeze = nv_mcp55_freeze,