Re: PATA -- pata_amd on 2.6.19 fails to IDENTIFY my DVD-ROM

Tejun Heo
2006-12-28T02:25:06Z

Rene Herman wrote:
> Tejun Heo wrote:
>
>> Rene Herman wrote:
>
>>> I just tried the PATA driver for my AMD756 chip. During boot, it hangs
>>> for 3 minutes failing to identify my DVD-ROM (secondary slave) and does
>>> not give me access to it after it timed out.
>>
>> Please give a shot at v2.6.20-rc2 and report what the kernel says.
>
> This IDENTIFY issue seems already fixed in -rc2. No more pause, and my
> DVD-ROM works fine again.

Great.

> Unfortunately, another issue seems to have
> cropped up. On 2.6.20-rc2, hdparm -t /dev/sda gets me ~ 24 M/s while
> both the old IDE driver and the 2.6.19 PATA driver do ~ 50 M/s
>
> 2.6.20-rc2-ata:
>
> # hdparm -t /dev/sda
>
> /dev/sda:
> Timing buffered disk reads: 72 MB in 3.03 seconds = 23.75 MB/sec
>
> 2.6.19-ata:
>
> # hdparm -t /dev/sda
>
> /dev/sda:
> Timing buffered disk reads: 150 MB in 3.00 seconds = 49.94 MB/sec

Everything seems fine in the dmesg. Performance degradation is probably
some other issue in -rc kernel. I'm suspecting recently fixed block
layer bug. If it's still the same in the next -rc, please report.

Thanks.

--
tejun