From: Ben Widawsky <ben@bwidawsk.net>
To: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 1/3] drm/i915: close PM interrupt masking races in the irq handler
Date: Sun, 4 Sep 2011 10:09:10 -0700 [thread overview]
Message-ID: <20110904100910.56ffb1f7@bwidawsk.net> (raw)
In-Reply-To: <1315150502-12537-2-git-send-email-daniel.vetter@ffwll.ch>
On Sun, 4 Sep 2011 17:35:00 +0200
Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> Quoting Chris Wilson's more concise description:
>
> "Ah I think I see the problem. As you point out we only mask the
> current interrupt received, so that if we have a task pending (and so
> IMR != 0) we actually unmask the pending interrupt and so could
> receive it again before the tasklet is finally kicked off by the
> grumpy scheduler."
>
> So we need the hw to issue PM interrupts A, B, A while the scheduler
> is hating us and refuses to run the rps work item. On receiving PM
> interrupt A we hit the
> WARN because
>
> dev_priv->pm_iir == PM_A | PM_B
>
> Also add a posting read as suggested by Chris to ensure proper
> ordering of the writes to PMIMR and PMIIR. Just in case somebody
> weakens write ordering.
>
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
next prev parent reply other threads:[~2011-09-04 17:08 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-04 3:24 [PATCH] drm/i915: Fix rps irq warning Ben Widawsky
2011-09-04 9:03 ` Chris Wilson
2011-09-04 15:49 ` Ben Widawsky
2011-09-04 15:34 ` [PATCH 0/3] slaughter rps races some more Daniel Vetter
2011-09-04 15:35 ` [PATCH 1/3] drm/i915: close PM interrupt masking races in the irq handler Daniel Vetter
2011-09-04 17:09 ` Ben Widawsky [this message]
2011-09-04 15:35 ` [PATCH 2/3] drm/i915: close PM interrupt masking races in the rps work func Daniel Vetter
2011-09-04 17:08 ` Ben Widawsky
2011-09-04 19:26 ` Daniel Vetter
2011-09-04 19:56 ` Ben Widawsky
2011-09-04 20:10 ` Daniel Vetter
2011-09-04 21:38 ` Ben Widawsky
2011-09-05 6:38 ` Daniel Vetter
2011-09-05 6:51 ` Ben Widawsky
2011-09-05 12:15 ` Chris Wilson
2011-09-04 15:35 ` [PATCH 3/3] drm/i915: close rps work vs. rps disable races Daniel Vetter
2011-09-04 17:23 ` Ben Widawsky
2011-09-04 19:17 ` Daniel Vetter
2011-09-04 19:50 ` Ben Widawsky
2011-09-04 19:57 ` Daniel Vetter
2011-09-05 8:15 ` [PATCH] drm/i915: properly cancel rps_work on module unload Daniel Vetter
2011-09-05 17:27 ` Ben Widawsky
2011-09-08 12:00 [PATCH 1/3] drm/i915: close PM interrupt masking races in the irq handler Daniel Vetter
2011-09-08 20:43 ` Chris Wilson
2011-09-23 16:08 ` Daniel Vetter
2012-04-15 9:06 ` Chris Wilson
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