lkml.org 
[lkml]   [2013]   [May]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/2] regmap: Make regmap-mmio usable from different contexts
On Thu, May 23, 2013 at 04:20:27PM +0200, Lars-Peter Clausen wrote:
> On 05/23/2013 04:05 PM, Mark Brown wrote:

> > This seems really invasive, why not just have the lock that gets passed
> > in point to a struct which has both the lock and the flags? As far as
> > the core is concerned the lock is just whatever data is required to do
> > the locking, the fact that it's actually two values is an implementation
> > detail of this locking implementation.

> I think that won't work. spin_lock_irqsave() will write to the flags
> parameter before it has successfully taken the look. So if a process running
> on another CPU tries to acquire the the lock while it is already held we'll
> end up overwriting the flags. E.g:

So you'd have to allocate a struct on the stack with a pointer and the
flags in it and initialise the pointer. Not awesome but not the end of
the world.
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2013-05-23 17:01    [W:0.169 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site