From: Jani Nikula <jani.nikula@linux.intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>,
Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915: Do graphics device reset under forcewake
Date: Thu, 05 Nov 2015 15:33:21 +0200 [thread overview]
Message-ID: <87y4eclgf2.fsf@intel.com> (raw)
In-Reply-To: <20151105113036.GY669@nuc-i3427.alporthouse.com>
On Thu, 05 Nov 2015, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> On Thu, Nov 05, 2015 at 01:11:38PM +0200, Mika Kuoppala wrote:
>> We have a timed release of a forcewake when using
>> I915_READ/WRITE macros. wait_for() macro will go to quite
>> long sleep if the first read doesn't satisfy the condition for
>> successful exit. With these two interacting, it is possible that
>> we lose the forcewake during the wait_for() and the subsequent read
>> will reaquire forcewake.
>>
>> Further experiments with skl shows that when we lose forcewake,
>> we lose the reset request we submitted. So reset request register
>> is not power context saved.
>>
>> Grab forcewakes for all engines before starting the reset/request
>> dance so that all requests stay valid for the duration of reset
>> requisition across all the engines.
>>
>> v2: Add comment on power well sleeps. Wrap the reset handling
>> under forcewake instead of just reset requests (Chris)
>>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92774
>> Cc: Chris Wilson <chris@chris-wilson.co.uk>
>> Tested-by: Tomi Sarvela <tomix.p.sarvela@intel.com> (v1, v2)
>> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Pushed to drm-intel-next-fixes, thanks for the patch and review.
BR,
Jani.
--
Jani Nikula, Intel Open Source Technology Center
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prev parent reply other threads:[~2015-11-05 13:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-04 9:33 [PATCH] drm/i915: Request for resets under forcewake Mika Kuoppala
2015-11-04 9:45 ` Chris Wilson
2015-11-04 10:13 ` Mika Kuoppala
2015-11-05 11:11 ` [PATCH] drm/i915: Do graphics device reset " Mika Kuoppala
2015-11-05 11:30 ` Chris Wilson
2015-11-05 13:33 ` Jani Nikula [this message]
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