lkml.org 
[lkml]   [2017]   [Oct]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH V8 00/14] mmc: Add Command Queue support
On Wed, Oct 11, 2017 at 3:58 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:

> Actually completing the request in the ->done callback, may still be
> possible, because in principle it only needs to inform the other
> prepared request that it may start, before it continues to post
> process/completes the current one.

I try to do that in this patch:
https://marc.info/?l=linux-mmc&m=148665460925587&w=2

I'm trying to rebase this work now.

> However, by looking at for example how mmci.c works, it actually holds
> its spinlock while it calls mmc_request_done(). The same spinlock is
> taken in the ->request() function, but not in the ->post_req()
> function. In other words, completing the request in the ->done()
> callback, would make mmci to keep the spinlock held throughout the
> post processing cycle, which then prevents the next request from being
> started.

It seems my patch would not deliver in some drivers until we look
into the locking semantics in the drivers.

Yours,
Linus Walleij

\
 
 \ /
  Last update: 2017-10-12 10:08    [W:0.594 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site