lkml.org 
[lkml]   [2018]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH RFC] scsi: ufs: Disable blk-mq for now
On Thu, Sep 13, 2018 at 03:15:39PM +0300, Adrian Hunter wrote:
> On 13/09/18 15:05, Ming Lei wrote:
> > On Thu, Sep 13, 2018 at 02:28:48PM +0300, Adrian Hunter wrote:
> >> blk-mq does not support runtime pm, so disable blk-mq support for now.
> >
> > So could you describe a bit what the issue you are trying to fix?
>
> UFS is a low-power solution, so we must be able to runtime suspend.
>
> >
> > This is host level runtime PM you are trying to address, and if blk-mq
> > runtime isn't enabled, I guess the host won't be runtime suspended at all
> > because some of its descendant are always active.
> >
> > So seems we need to do nothing for preventing the host controller from
> > entering runtime suspend.
>
> We don't want to prevent the host controller from runtime suspending, quite
> the opposite.

OK, got it.

However, in previous discussion, it is strongly objected to use
per-driver/device .use_blk_mq switch, so not sure if this way can
be accepted.

BTW, I just posted the runtime PM enablement patches[1] for blk-mq,
and I verified that it works fine and passed blktests & xfstest & my
other sanity tests, could you try it on UFS?

[1] https://marc.info/?l=linux-block&m=153684095523409&w=2

Thanks,
Ming

\
 
 \ /
  Last update: 2018-09-14 03:53    [W:0.055 / U:1.644 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site