Attachment 113109 Details for Bug 88933 – drm/i915: Remove bogus locking check in the hangcheck code

[patch] drm/i915: Remove bogus locking check in the hangcheck code

0001-drm-i915-Remove-bogus-locking-check-in-the-hangcheck.patch (text/plain), 1.69 KB, created by Mika Kuoppala on 2015-02-03 13:25:00 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Mika Kuoppala

Created: 2015-02-03 13:25:00 UTC

Size: 1.69 KB

patch

obsolete

>From b29def94757f89028ddef3fee1aba7d95f34a973 Mon Sep 17 00:00:00 2001
>From: Daniel Vetter <daniel.vetter@ffwll.ch>
>Date: Tue, 3 Feb 2015 11:49:00 +0100
>Subject: [PATCH] drm/i915: Remove bogus locking check in the hangcheck code
>
>You can _never_ assert that a lock is not held, except in some very
>restricted corner cases where it's guranteed that your code is running
>single-threade (e.g. driver load before you've published any pointers
>leading to that lock).
>
>In addition the early return breaks a bunch of testcases since with
>highly concurrent hangcheck stress tests the reset fails to work and
>the test doesn't recover and time out.
>
>This regression has been introduced in
>
>commit b8d24a06568368076ebd5a858a011699a97bfa42
>Author: Mika Kuoppala <mika.kuoppala@linux.intel.com>
>Date:   Wed Jan 28 17:03:14 2015 +0200
>
>    drm/i915: Remove nested work in gpu error handling
>
>Aside: It is possible to check whether a given task doesn't hold a
>lock, but only when lockdep is enabled, using the lockdep_assert_held
>stuff.
>
>Cc: Chris Wilson <chris@chris-wilson.co.uk>
>Cc: Mika Kuoppala <mika.kuoppala@intel.com>
>Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
>---
> drivers/gpu/drm/i915/i915_irq.c | 3 ---
> 1 file changed, 3 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
>index 53c5f9e..4145d95 100644
>--- a/drivers/gpu/drm/i915/i915_irq.c
>+++ b/drivers/gpu/drm/i915/i915_irq.c
>@@ -2612,9 +2612,6 @@ void i915_handle_error(struct drm_device *dev, bool wedged,
> 	va_list args;
> 	char error_msg[80];
> 
>-	if (WARN_ON(mutex_is_locked(&dev_priv->dev->struct_mutex)))
>-		return;
>-
> 	va_start(args, fmt);
> 	vscnprintf(error_msg, sizeof(error_msg), fmt, args);
> 	va_end(args);
>-- 
>1.9.1
>

Actions: View | Splinter Review

Attachments on bug 88933: 113086 | 113105 | 113109 | 113335

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.