lkml.org 
[lkml]   [2017]   [Dec]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6 4/5] clk: aspeed: Register gated clocks
On 12/22, Benjamin Herrenschmidt wrote:
> On Fri, 2017-12-22 at 13:36 +1100, Benjamin Herrenschmidt wrote:
> >
> > > No you can't sleep here. It needs to delay because this is inside
> > > spinlock_irqsave.
> >
> > Additionally you really don't want to delay for 10ms with interrupts
> > off :-(
> >
> > Sadly, it looks like the clk framework already calls you with spinlock
> > irqsafe, which is a rather major suckage.
> >
> > Stephen, why is that so ? That pretty much makes it impossible to
> > do sleeping things, which prevents things like i2c based clock
> > controllers etc...
>
> I noticed we do have a few i2c based clock drivers... how are they ever
> supposed to work ? i2c bus controllers are allowed to sleep and the i2c
> core takes mutexes...

We have clk_prepare()/clk_unprepare() for sleeping suckage. You
can use that, and i2c based clk drivers do that today.

--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

\
 
 \ /
  Last update: 2017-12-27 02:32    [W:0.107 / U:0.816 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site