Attachment 42635 Details for Bug 29230 – Don't switch fb after a no-op (when disabling)

[patch] Don't switch fb after a no-op (when disabling)

0001-drm-Don-t-switch-fb-when-disabling-an-output.patch (text/plain), 1.63 KB, created by Chris Wilson on 2011-01-28 04:03:09 UTC

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Creator: Chris Wilson

Created: 2011-01-28 04:03:09 UTC

Size: 1.63 KB

patch

obsolete

>From 31b9644bf2d58aa1cefde84be018c1c1762198a5 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Fri, 28 Jan 2011 11:53:03 +0000
>Subject: [PATCH] drm: Don't switch fb when disabling an output
>
>In drm_crtc_helper_set_config, we call drm_crtc_helper_set_mode which
>may return early and do no operation if the crtc is to be disabled. In
>this case we merrily swap to the new fb, discarding the old_fb believing
>that it has been cleaned up. However, due to the early return, the
>old_fb was not presented to the backend for correct reaping, and nor was
>the new one - which is about to be reaped via the
>drm_helper_disable_unused_functions(), leading to incorrect refcounting
>of the pinned objects.
>
>Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=27722
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29857
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29230
>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>---
> drivers/gpu/drm/drm_crtc_helper.c |    4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
>index 44be7b8..b6719995 100644
>--- a/drivers/gpu/drm/drm_crtc_helper.c
>+++ b/drivers/gpu/drm/drm_crtc_helper.c
>@@ -642,8 +642,8 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
> 		mode_changed = true;
> 
> 	if (mode_changed) {
>-		set->crtc->enabled = (set->mode != NULL);
>-		if (set->mode != NULL) {
>+		set->crtc->enabled = drm_helper_crtc_in_use(set->crtc);
>+		if (set->crtc->enabled) {
> 			DRM_DEBUG_KMS("attempting to set mode from"
> 					" userspace\n");
> 			drm_mode_debug_printmodeline(set->mode);
>-- 
>1.7.2.3
>

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