lkml.org 
[lkml]   [2011]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: pull request: wireless 2011-11-22
On Tue, Nov 22, 2011 at 04:13:22PM -0500, David Miller wrote:
> From: David Miller <davem@davemloft.net>
> Date: Tue, 22 Nov 2011 16:05:11 -0500 (EST)
>
> > From: "John W. Linville" <linville@tuxdriver.com>
> > Date: Tue, 22 Nov 2011 15:56:55 -0500
> >
> >> On Tue, Nov 22, 2011 at 03:14:29PM -0500, David Miller wrote:
> >>> From: "John W. Linville" <linville@tuxdriver.com>
> >>> Date: Tue, 22 Nov 2011 14:35:05 -0500
> >>>
> >>> > Here is the latest batch of fixes intended for 3.2. This includes a
> >>> > correction for a user-visible error in mac80211's debugfs info, a fix
> >>> > for a potential memory corrupter in prism54, an endian fix for rt2x00,
> >>> > an endian fix for mac80211, a fix for a NULL derefernce in cfg80211, a
> >>> > locking fix and a deadlock fix for p54spi, and a pair of rt2x00 fixes
> >>> > for handling some spurious interrupts that hardware can generate.
> >>> >
> >>> > Please let me know if there are problems!
> >>>
> >>> The rt2800pci change doesn't look correct.
> >>>
> >>> If the IRQ line is shared with another device, this change will make it
> >>> never see interrupts. Once you say "IRQ_HANDLED" the IRQ dispatch
> >>> stops processing the interrupt handler list.
> >>
> >> I thought this at first as well. But looking at the code in
> >> kernel/irq/handle.c doesn't support that conclusion. In fact, every
> >> handler gets invoked no matter what they all return. All of the irq
> >> handler return values are ORed together and passed to note_interrupt.
> >> Only if every irq handler returns IRQ_NONE does the code in
> >> kernel/irq/spurious.c start getting involved.
> >>
> >> Anyway, this seems to be safe even for shared interrupts. That said,
> >> this is a bit ugly. But it makes a serious difference in performance
> >> for those afflicted with this issue.
> >
> > It just means that we won't notice spurious interrupts if the device
> > sharing the line with rt2800pci generates one.
> >
> > This change is wrong.
>
> BTW, look at it this way, if what you say is true John then what's the point
> in returning any specific value at all?
>
> Everyone can just return IRQ_HANDLED and everything would just work.
>
> But you know that's not the case, and that it's important that this value
> is returned accurately.

Alright, that a good point. I'll drop those two patches.

John
--
John W. Linville Someday the world will need a hero, and you
linville@tuxdriver.com might be all we have. Be ready.


\
 
 \ /
  Last update: 2011-11-22 22:33    [W:0.053 / U:2.076 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site