Re: [PATCH 1/1] scsi: retrieve cache mode using ATA_16 if normal routine fails

Amit Sahrawat
2011-12-14T03:44:19Z

Hi Jeff/James,

Just to add a thought - this issues is not related with ATA, this is
primarily related with HDD's with a USB interface i.e., SCSI <-> USB.
And, when I check my kernel config, CONFIG_ATA is not selected,
libata-scsi - this gets compiled only in case CONFIG_ATA is on.
Are these two things inter-related?

Please let us know.

Thanks & Regards,
Amit Sahrawat

On Wed, Dec 14, 2011 at 2:08 AM, Jeff Garzik <jeff@garzik.org> wrote:
> On 12/13/2011 03:53 AM, James Bottomley wrote:
>>
>> On Tue, 2011-12-13 at 09:20 +0900, Namjae Jeon wrote:
>>>>
>>>> This whole patch looks like a layering violation.  Why not just update
>>>> the SAT layer to translate the MODE SENSE correctly?
>>>
>>> Would plz you explain more ? I didn't clearly understand your point yet.
>>
>>
>> The ATA layer does translation for SCSI commands.  Just translate the
>> mode sense correctly to use IDENTIFY word 85.  It's a smaller patch and
>> no need for any changes in SCSI.
>
>
> Correct.
>
>
>> Actually, looking at it, it seems to be correct ... why is it not
>> working for you?
>
>
> Indeed -- the patch attempts to address a problem that the libata-scsi
> translation module already handles.
>
> I would look at why the device is not properly reporting that already. If
> necessary, we would update libata not SCSI.
>
>        Jeff
>
>