Re: [patch ide-dev 8/9] make ide_task_ioctl() use REQ_DRIVE_TASKFILE

[Tejun Heo]

 Hi,

Bartlomiej Zolnierkiewicz wrote:
> On Sunday 27 February 2005 08:36, Tejun Heo wrote:
>
> > Hello, Bartlomiej.
> >
> > This patch should be modified to use flagged taskfile if the
> > task_end_request_fix patch isn't applied.  As non-flagged taskfile
> > won't return valid result registers, TASK ioctl users won't get the
> > correct register output.
>
>
> Nope, it works just fine because REQ_DRIVE_TASK used only
> no-data protocol, please check task_no_data_intr().

 Sorry, I missed that.  IDE really has a lot of ways to finish a 
command, doesn't it?  hdio.txt is gonna look ugly. :-)

> > IMHO, this flag-to-get-result-registers thing is way too subtle.  How
> > about keeping old behavior by just not copying out register outputs in
> > ide_taskfile_ioctl() in applicable cases instead of not reading
> > registers when ending commands?  That is, unless there's some
> > noticeable performance impacts I'm not aware of.
>
>
> This would miss whole point of not _reading_ these registers (IO is slow).
> IMHO new flags denoting {in,out} registers should be added (to <linux/ata.h>
> to share them with libata) so new code can be sane and old flags would map
> on new flags when needed.

 Please do it.

 Or, let me know what you have in mind (added fields, flag names, 
etc...); then, I'll do it.  I think we also need to hear Jeff's opinion 
as things need to be added to ata.h.

 Thanks.

--
tejun

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