* [PATCH 1/3] Revert "drm/fb-helper: Remove damage worker"
2022-11-18 13:35 [PATCH 0/3] drm/fb-helper: Restore damage worker Thomas Zimmermann
@ 2022-11-18 13:35 ` Thomas Zimmermann
2022-11-18 13:35 ` [PATCH 2/3] Revert "drm/fb-helper: Schedule deferred-I/O worker after writing to framebuffer" Thomas Zimmermann
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Thomas Zimmermann @ 2022-11-18 13:35 UTC (permalink / raw)
To: daniel, airlied, maarten.lankhorst, mripard; +Cc: Thomas Zimmermann, dri-devel
This reverts commit 27c3e9452d552ea86369a94f23287a9675f2d7a1.
Needed to restore the fbdev damage worker. There have been bug reports
about locking order [1] and incorrectly takens branches. [2] Restore
the damage worker until these problems have been resovled.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html # 1
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a # 2
---
drivers/gpu/drm/drm_fb_helper.c | 9 +++++++++
include/drm/drm_fb_helper.h | 2 ++
2 files changed, 11 insertions(+)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index a1f86e436ae8e..c0e9a977a3b3c 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -403,6 +403,13 @@ static void drm_fb_helper_fb_dirty(struct drm_fb_helper *helper)
spin_unlock_irqrestore(&helper->damage_lock, flags);
}
+static void drm_fb_helper_damage_work(struct work_struct *work)
+{
+ struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper, damage_work);
+
+ drm_fb_helper_fb_dirty(helper);
+}
+
/**
* drm_fb_helper_prepare - setup a drm_fb_helper structure
* @dev: DRM device
@@ -418,6 +425,7 @@ void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
INIT_LIST_HEAD(&helper->kernel_fb_list);
spin_lock_init(&helper->damage_lock);
INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
+ INIT_WORK(&helper->damage_work, drm_fb_helper_damage_work);
helper->damage_clip.x1 = helper->damage_clip.y1 = ~0;
mutex_init(&helper->lock);
helper->funcs = funcs;
@@ -549,6 +557,7 @@ void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
return;
cancel_work_sync(&fb_helper->resume_work);
+ cancel_work_sync(&fb_helper->damage_work);
info = fb_helper->info;
if (info) {
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 455f6c2b8117a..b111dc7ada78d 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -116,6 +116,7 @@ struct drm_fb_helper_funcs {
* @damage_clip: clip rectangle used with deferred_io to accumulate damage to
* the screen buffer
* @damage_lock: spinlock protecting @damage_clip
+ * @damage_work: worker used to flush the framebuffer
* @resume_work: worker used during resume if the console lock is already taken
*
* This is the main structure used by the fbdev helpers. Drivers supporting
@@ -145,6 +146,7 @@ struct drm_fb_helper {
u32 pseudo_palette[17];
struct drm_clip_rect damage_clip;
spinlock_t damage_lock;
+ struct work_struct damage_work;
struct work_struct resume_work;
/**
--
2.38.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/3] Revert "drm/fb-helper: Schedule deferred-I/O worker after writing to framebuffer"
2022-11-18 13:35 [PATCH 0/3] drm/fb-helper: Restore damage worker Thomas Zimmermann
2022-11-18 13:35 ` [PATCH 1/3] Revert "drm/fb-helper: Remove damage worker" Thomas Zimmermann
@ 2022-11-18 13:35 ` Thomas Zimmermann
2022-11-18 13:35 ` [PATCH 3/3] Revert "drm/fb-helper: Perform damage handling in deferred-I/O helper" Thomas Zimmermann
2022-11-19 11:15 ` [PATCH 0/3] drm/fb-helper: Restore damage worker Daniel Vetter
3 siblings, 0 replies; 5+ messages in thread
From: Thomas Zimmermann @ 2022-11-18 13:35 UTC (permalink / raw)
To: daniel, airlied, maarten.lankhorst, mripard; +Cc: Thomas Zimmermann, dri-devel
This reverts commit 7f5cc4a3e5e4c5a38e5748defc952e45278f7a70.
Needed to restore the fbdev damage worker. There have been bug reports
about locking order [1] and incorrectly takens branches. [2] Restore
the damage worker until these problems have been resovled.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html # 1
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a # 2
---
drivers/gpu/drm/drm_fb_helper.c | 9 +--------
drivers/video/fbdev/core/fb_defio.c | 16 ----------------
include/linux/fb.h | 1 -
3 files changed, 1 insertion(+), 25 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index c0e9a977a3b3c..cdbf03e941b2b 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -599,16 +599,9 @@ static void drm_fb_helper_add_damage_clip(struct drm_fb_helper *helper, u32 x, u
static void drm_fb_helper_damage(struct drm_fb_helper *helper, u32 x, u32 y,
u32 width, u32 height)
{
- struct fb_info *info = helper->info;
-
drm_fb_helper_add_damage_clip(helper, x, y, width, height);
- /*
- * The current fbdev emulation only flushes buffers if a damage
- * update is necessary. And we can assume that deferred I/O has
- * been enabled as damage updates require deferred I/O for mmap.
- */
- fb_deferred_io_schedule_flush(info);
+ schedule_work(&helper->damage_work);
}
/*
diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
index dec678f72a42f..c730253ab85ce 100644
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -332,19 +332,3 @@ void fb_deferred_io_cleanup(struct fb_info *info)
mutex_destroy(&fbdefio->lock);
}
EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);
-
-void fb_deferred_io_schedule_flush(struct fb_info *info)
-{
- struct fb_deferred_io *fbdefio = info->fbdefio;
-
- if (WARN_ON_ONCE(!fbdefio))
- return; /* bug in driver logic */
-
- /*
- * There's no requirement from callers to schedule the
- * flush immediately. Rather schedule the worker with a
- * delay and let a few more writes pile up.
- */
- schedule_delayed_work(&info->deferred_work, fbdefio->delay);
-}
-EXPORT_SYMBOL_GPL(fb_deferred_io_schedule_flush);
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 3a822e4357b12..e6b8e7ad7ac80 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -663,7 +663,6 @@ extern void fb_deferred_io_open(struct fb_info *info,
struct inode *inode,
struct file *file);
extern void fb_deferred_io_cleanup(struct fb_info *info);
-extern void fb_deferred_io_schedule_flush(struct fb_info *info);
extern int fb_deferred_io_fsync(struct file *file, loff_t start,
loff_t end, int datasync);
--
2.38.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 3/3] Revert "drm/fb-helper: Perform damage handling in deferred-I/O helper"
2022-11-18 13:35 [PATCH 0/3] drm/fb-helper: Restore damage worker Thomas Zimmermann
2022-11-18 13:35 ` [PATCH 1/3] Revert "drm/fb-helper: Remove damage worker" Thomas Zimmermann
2022-11-18 13:35 ` [PATCH 2/3] Revert "drm/fb-helper: Schedule deferred-I/O worker after writing to framebuffer" Thomas Zimmermann
@ 2022-11-18 13:35 ` Thomas Zimmermann
2022-11-19 11:15 ` [PATCH 0/3] drm/fb-helper: Restore damage worker Daniel Vetter
3 siblings, 0 replies; 5+ messages in thread
From: Thomas Zimmermann @ 2022-11-18 13:35 UTC (permalink / raw)
To: daniel, airlied, maarten.lankhorst, mripard; +Cc: Thomas Zimmermann, dri-devel
This reverts commit 5fc586a058babc71c82a038477581b7bfe1c6e2a.
Needed to restore the fbdev damage worker. There have been bug reports
about locking order [1] and incorrectly takens branches. [2] Restore
the damage worker until these problems have been resovled.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html # 1
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a # 2
---
drivers/gpu/drm/drm_fb_helper.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index cdbf03e941b2b..b3a731b9170a6 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -666,16 +666,10 @@ void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagerefli
if (min_off < max_off) {
drm_fb_helper_memory_range_to_clip(info, min_off, max_off - min_off, &damage_area);
- drm_fb_helper_add_damage_clip(helper, damage_area.x1, damage_area.y1,
- drm_rect_width(&damage_area),
- drm_rect_height(&damage_area));
+ drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
+ drm_rect_width(&damage_area),
+ drm_rect_height(&damage_area));
}
-
- /*
- * Flushes all dirty pages from mmap's pageref list and the
- * areas that have been written by struct fb_ops callbacks.
- */
- drm_fb_helper_fb_dirty(helper);
}
EXPORT_SYMBOL(drm_fb_helper_deferred_io);
--
2.38.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 0/3] drm/fb-helper: Restore damage worker
2022-11-18 13:35 [PATCH 0/3] drm/fb-helper: Restore damage worker Thomas Zimmermann
` (2 preceding siblings ...)
2022-11-18 13:35 ` [PATCH 3/3] Revert "drm/fb-helper: Perform damage handling in deferred-I/O helper" Thomas Zimmermann
@ 2022-11-19 11:15 ` Daniel Vetter
3 siblings, 0 replies; 5+ messages in thread
From: Daniel Vetter @ 2022-11-19 11:15 UTC (permalink / raw)
To: Thomas Zimmermann; +Cc: dri-devel
On Fri, Nov 18, 2022 at 02:35:32PM +0100, Thomas Zimmermann wrote:
> It turns out that the removal of the damage worker can lead to
> locking cycles. The display update now runs while holding the
> fbdefio lock, which conflicts with locks in the modesetting code
> that updates the display. There's no easy fix for this, so let's
> restore the damage worker. The display update will then again run
> outside of the fbdefio lock.
>
> See [1] for bug reports.
>
> [1] https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html
:-(
> Thomas Zimmermann (3):
> Revert "drm/fb-helper: Remove damage worker"
> Revert "drm/fb-helper: Schedule deferred-I/O worker after writing to
> framebuffer"
> Revert "drm/fb-helper: Perform damage handling in deferred-I/O helper"
On the series: Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Apologies for the late ack, I wasn't around yesterday afternoon.
-Daniel
>
> drivers/gpu/drm/drm_fb_helper.c | 30 +++++++++++++----------------
> drivers/video/fbdev/core/fb_defio.c | 16 ---------------
> include/drm/drm_fb_helper.h | 2 ++
> include/linux/fb.h | 1 -
> 4 files changed, 15 insertions(+), 34 deletions(-)
>
> --
> 2.38.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
^ permalink raw reply [flat|nested] 5+ messages in thread