Attachment 63020 Details for Bug 50772 – properly delay fbcon hotplug handling

[patch] properly delay fbcon hotplug handling

0001-drm-fb-helper-delay-hotplug-handling-when-partially-.patch (text/plain), 2.42 KB, created by Daniel Vetter on 2012-06-14 05:10:56 UTC

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Creator: Daniel Vetter

Created: 2012-06-14 05:10:56 UTC

Size: 2.42 KB

patch

obsolete

>From 39a456166f123178861cfce379fb8afe21bbe241 Mon Sep 17 00:00:00 2001
>From: Daniel Vetter <daniel.vetter@ffwll.ch>
>Date: Thu, 14 Jun 2012 14:04:39 +0200
>Subject: [PATCH] drm/fb-helper: delay hotplug handling when partially bound
>
>Ok, this requires quite a dance to actually hit:
>1) We plug in a 2nd screen, enable it in both X and (by vt-switching)
>in the fbcon.
>2) We disable that screen again in with xrandr.
>3) We vt-switch again, so that fbcon displays on the 2nd screen, but X
>on the first screen.
>3) When X controls the vt, we unplug that screen.
>
>Now drm_fb_helper_hotplug_event we noticed that that some crtcs are
>bound, but because we still have the fbcon on the 2nd screeen we also
>have bound set. Which means the fbcon wrongly assumes it's in control
>of everything an happily disables the output on the 2nd screen, but
>enables its fb on the first screen.
>
>Work around this issue by counting how many crtcs are bound and how
>many are bound to fbcon and assuming that when fbcon isn't bound to
>all of them, it better not touch the output configuration.
>
>Conceptually this is the same as only restoring the fbcon output
>configuration on the driver's ->lastclose, when we're sure that no one
>else is using kms. So this should be consistent with existing kms
>drivers.
>
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50772
>Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>---
> drivers/gpu/drm/drm_fb_helper.c |    8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
>diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>index 5683b7f..d3f15b9 100644
>--- a/drivers/gpu/drm/drm_fb_helper.c
>+++ b/drivers/gpu/drm/drm_fb_helper.c
>@@ -1353,7 +1353,7 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
> 	struct drm_device *dev = fb_helper->dev;
> 	int count = 0;
> 	u32 max_width, max_height, bpp_sel;
>-	bool bound = false, crtcs_bound = false;
>+	int bound = 0, crtcs_bound = 0;
> 	struct drm_crtc *crtc;
> 
> 	if (!fb_helper->fb)
>@@ -1362,12 +1362,12 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
> 	mutex_lock(&dev->mode_config.mutex);
> 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
> 		if (crtc->fb)
>-			crtcs_bound = true;
>+			crtcs_bound++;
> 		if (crtc->fb == fb_helper->fb)
>-			bound = true;
>+			bound++;
> 	}
> 
>-	if (!bound && crtcs_bound) {
>+	if (bound < crtcs_bound) {
> 		fb_helper->delayed_hotplug = true;
> 		mutex_unlock(&dev->mode_config.mutex);
> 		return 0;
>-- 
>1.7.10
>

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Attachments on bug 50772: 62651 | 62652 | 62653 | 62654 | 62931 | 63020

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