drm/gud: Don't retry a failed framebuffer flush

If a framebuffer flush fails the driver will do one retry by requeing the
worker. Currently the worker is used even for synchronous flushing, but a
later patch will inline it, so this needs to change. Thinking about how to
solve this I came to the conclusion that this retry mechanism was a fix
for a problem that was only in the mind of the developer (me) and not
something that solved a real problem.

So let's remove this for now and revisit later should it become necessary.
gud_add_damage() has now only one caller so it can be inlined.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-2-435037990a83@tronnes.org

diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c
index 61f4abaf1811f5225e757695c1f0fbb342a04d31..ff1358815af520388183a058a146484e0d5216ad 100644 (file)
--- a/drivers/gpu/drm/gud/gud_pipe.c
+++ b/drivers/gpu/drm/gud/gud_pipe.c
@@ -333,37 +333,6 @@ void gud_clear_damage(struct gud_device *gdrm)
        gdrm->damage.y2 = 0;
 }
 
-static void gud_add_damage(struct gud_device *gdrm, struct drm_rect *damage)
-{
-       gdrm->damage.x1 = min(gdrm->damage.x1, damage->x1);
-       gdrm->damage.y1 = min(gdrm->damage.y1, damage->y1);
-       gdrm->damage.x2 = max(gdrm->damage.x2, damage->x2);
-       gdrm->damage.y2 = max(gdrm->damage.y2, damage->y2);
-}
-
-static void gud_retry_failed_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
-                                  struct drm_rect *damage)
-{
-       /*
-        * pipe_update waits for the worker when the display mode is going to change.
-        * This ensures that the width and height is still the same making it safe to
-        * add back the damage.
-        */
-
-       mutex_lock(&gdrm->damage_lock);
-       if (!gdrm->fb) {
-               drm_framebuffer_get(fb);
-               gdrm->fb = fb;
-       }
-       gud_add_damage(gdrm, damage);
-       mutex_unlock(&gdrm->damage_lock);
-
-       /* Retry only once to avoid a possible storm in case of continues errors. */
-       if (!gdrm->prev_flush_failed)
-               queue_work(system_long_wq, &gdrm->work);
-       gdrm->prev_flush_failed = true;
-}
-
 void gud_flush_work(struct work_struct *work)
 {
        struct gud_device *gdrm = container_of(work, struct gud_device, work);
@@ -407,14 +376,10 @@ void gud_flush_work(struct work_struct *work)
                ret = gud_flush_rect(gdrm, fb, format, &rect);
                if (ret) {
                        if (ret != -ENODEV && ret != -ECONNRESET &&
-                           ret != -ESHUTDOWN && ret != -EPROTO) {
-                               bool prev_flush_failed = gdrm->prev_flush_failed;
-
-                               gud_retry_failed_flush(gdrm, fb, &damage);
-                               if (!prev_flush_failed)
-                                       dev_err_ratelimited(fb->dev->dev,
-                                                           "Failed to flush framebuffer: error=%d\n", ret);
-                       }
+                           ret != -ESHUTDOWN && ret != -EPROTO)
+                               dev_err_ratelimited(fb->dev->dev,
+                                                   "Failed to flush framebuffer: error=%d\n", ret);
+                       gdrm->prev_flush_failed = true;
                        break;
                }
 
@@ -439,7 +404,10 @@ static void gud_fb_queue_damage(struct gud_device *gdrm, struct drm_framebuffer
                gdrm->fb = fb;
        }
 
-       gud_add_damage(gdrm, damage);
+       gdrm->damage.x1 = min(gdrm->damage.x1, damage->x1);
+       gdrm->damage.y1 = min(gdrm->damage.y1, damage->y1);
+       gdrm->damage.x2 = max(gdrm->damage.x2, damage->x2);
+       gdrm->damage.y2 = max(gdrm->damage.y2, damage->y2);
 
        mutex_unlock(&gdrm->damage_lock);