Re: [PATCH 03/10] block: add rq->resid_len

Tejun Heo
2009-04-30T09:30:37Z

Borislav Petkov wrote:
>>> And I like it too, we've been coming up with all sorts of hacks in
>>> ide-atapi wrt to residual completion and accounting of what got xferred
>>> already and rq->resid_len is much more cleaner, IMHO.
>>>
>>> /me testing...
>> AFAICT, residual count handling in ide was most broken.

Oooh... It was "mostly broken" not "most broken". Where went my l and
y?

> Tell me about it :).
>
>> This patch doesn't fix anything other than making it report 0
>> resid_len on SG_IO which is usually better than reporting full
>> residual count. The only place inside ide where residual count is used
>> in the tape driver to determine actually transferred size. That part
>> works okay with the patch applied.
>
>> Hmmm... maybe it's about time to finally clean up residual count
>> handling in ide and libata, which BTW doesn't do anything about it at
>> the moment.
>
> Completely agreed. This doesn't do anything about it right now but
> with rq->resid_len in place I could get rid of a bunch of pc->xferred,
> cmd->nleft and similar on-stack structs we've been introducing, and use
> solely an rq in the LLD. I'll get to do some experimenting tomorrow and
> whip up some cleanup patches in order to see how it could look exactly.
> Stay tuned.

Yay, cool. :-)

--
tejun