Re: [PATCH RFC] apm-emulation: apm_mutex breaks ACK; remove it

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, 13 May 2011, Paul Parsons wrote:

> apm_mutex is locked by a process (e.g. apm -s) at the start of 
> apm_ioctl() and remains locked while pm_suspend() is called. Any 
> subsequent process trying to ACK the suspend (e.g. apmd) is then blocked 
> at the start of apm_ioctl(), causing the suspend to be delayed for 5 
> seconds in apm_suspend_notifier() while the ACK times out. In short, 
> ACKs don't work.
> 
> The driver's data structures are sufficiently protected by assorted 
> locks. And pm_suspend() has its own mutex to prevent reentrancy. 
> Consequently there is no obvious requirement for apm_mutex, which 
> evolved from earlier BKL calls. So let's remove it.
>
> 
> Signed-off-by: Paul Parsons <lost.distance@xxxxxxxxx>
> ---
> This patch supersedes my previous "apm-emulation: Fix mutex race condition" patch; this patch fixes that earlier bug too.

Looks good to me (and sorry for the delay). Thanks Paul, will apply.

-- 
Jiri Kosina
SUSE Labs
_______________________________________________
linux-pm mailing list
linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linux-foundation.org/mailman/listinfo/linux-pm


[Index of Archives]     [Linux ACPI]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [CPU Freq]     [Kernel Newbies]     [Fedora Kernel]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux