Re: libata/PATA: GPCMD_SET_STREAMING via SG_IO does nothing

[Mark Lord <liml@rtr.ca>]

Sebastian Kemper wrote:
> Hi Alan!
> 
> On Tue, Nov 13, 2007 at 09:22:30PM +0000, Alan Cox wrote:
>> It isn't a known issue, and it suprises me as SG_IO basically passes
>> commands through to the drive. We don't support speed change via xfermode
>> setting but GPCMD_SET_STREAMING sohuld behave.
>>
>> Do you have a simple code example that shows the problem ?
> 
> http://svn.mplayerhq.hu/mplayer/trunk/stream/stream_dvd.c?view=markup
> 
> See dvd_set_speed(). The drive I'm using is an Optiarc DVD RW AD-7170A.
> With the "old" ATA driver dvd_set_speed() works, with libata it doesn't.
..

I think the problem here might be that libata doesn't actually support SG_IO
for ATAPI drives prior to 2.6.24 (ugh).

Try it with a 2.6.24-rc* kernel from kernel.org, or back-patch the ATA_16
SG_IO support into your older kernel.

Cheers