Re: [patch 05/25] ata: add the SW NCQ support to sata_nv for MCP51/MCP55/MCP61

[Jeff Garzik <jeff@garzik.org>]

Zoltan Boszormenyi wrote:
> Jeff Garzik írta:
>> Zoltan Boszormenyi wrote:
>>> Hi,
>>>
>>> Jeff Garzik írta:
>>>> akpm@linux-foundation.org wrote:
>>>>> From: Kuan Luo <kluo@nvidia.com>
>>>>>
>>>>> Add the Software NCQ support to sata_nv.c for MCP51/MCP55/MCP61 SATA
>>>>> controller.  NCQ function is disable by default, you can enable it 
>>>>> with
>>>>> 'swncq=1'.  NCQ will be turned off if the drive is Maxtor on MCP51 
>>>>> or MCP55
>>>>> rev 0xa2 platform.
>>>>>
>>>>> [akpm@linux-foundation.org: build fix]
>>>>> Signed-off-by: Kuan Luo <kluo@nvidia.com>
>>>>> Signed-off-by: Peer Chen <pchen@nvidia.com>
>>>>> Cc: Zoltan Boszormenyi <zboszor@dunaweb.hu>
>>>>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>>>>> ---
>>>>>
>>>>>  drivers/ata/sata_nv.c |  860 +++++++++++++++++++++++++++++++++++++++-
>>>>>  1 files changed, 851 insertions(+), 9 deletions(-)
>>>>
>>>> I finally gave this a thorough review.
>>>>
>>>> Overall, good work.  The state transitions all seem solid.  I made 
>>>> several minor changes and cleanups, and checked it into the 
>>>> 'nv-swncq' branch of 
>>>> git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev.git
>>>>
>>>> Two hurdles before I'm ready to push upstream:
>>>>
>>>> * someone please verify my minor changes did not break anything; I 
>>>> don't have real hardware
>>>
>>> After reading the diff between the original and your cleaned up version
>>> it seems both the change from 4 individual flags to a single integer 
>>> and the
>>> nv_swncq_bmdma_stop() -> __ata_bmdma_stop() transition are obviously 
>>> correct.
>>> I attached a small cleanup patch which may make one check a bit more 
>>> readable.
>>>
>>> However, can you explain this chunk below? Why isn't it needed?
>>>
>>> @@ -615,7 +622,6 @@ static const struct ata_port_info nv_por
>>>        {
>>>                .sht            = &nv_swncq_sht,
>>>                .flags          = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY,
>>> -               .link_flags     = ATA_LFLAG_HRST_TO_RESUME,
>>>                .pio_mask       = NV_PIO_MASK,
>>>                .mwdma_mask     = NV_MWDMA_MASK,
>>>                .udma_mask      = NV_UDMA_MASK,
>>
>> that's a bug.  fixed.
>>
>> I also applied your cleanup.
> 
> Thanks, but you took the wrong cleanup patch.
> My original, i.e. this chunk below is wrong.
> 
> @@ -2291,8 
> <http://git.kernel.org/?p=linux/kernel/git/jgarzik/libata-dev.git;a=blob;f=drivers/ata/sata_nv.c;h=540f218e10e56c8a85a937bc920a5d96434bcc8f;hb=41f0f8af3edfccd58b5c9d714928d773a072b693#l2291> 
> +2283,7 
> <http://git.kernel.org/?p=linux/kernel/git/jgarzik/libata-dev.git;a=blob;f=drivers/ata/sata_nv.c;h=ffd00f5c533d7b58dde67cfef7d2191ca15ea140;hb=5a5a9e1890b8260686218a68862d880daee1a817#l2283> 
> @@ static void nv_swncq_host_interrupt(struct ata_port *ap, u16 fis)
>                 */
>                pp->dhfis_bits |= (0x1 << pp->last_issue_tag);
>                pp->ncq_flags |= ncq_saw_d2h;
> -               if ((pp->ncq_flags & ncq_saw_sdb) ||
> -                   (pp->ncq_flags & ncq_saw_backout)) {
> +               if (pp->ncq_flags & (ncq_saw_sdb || ncq_saw_backout)) {
>                        ata_ehi_push_desc(ehi, "illegal fis transaction");
>                        ehi->err_mask |= AC_ERR_HSM;
>                        ehi->action |= ATA_EH_HARDRESET;
> 
> It should be a binary OR between the flags. This caused immediate
> NCQ errors upon boot and lead to disabling NCQ.
> My second patch has it corrected.

fixed