On 12/06/2023 11:21, Thomas Zimmermann wrote:
Hi
Am 12.06.23 um 05:16 schrieb Dmitry Baryshkov:
Since commit 93e81e38e197 ("drm/fb_helper: Minimize damage-helper
overhead") the drm_fb_helper_funcs::fb_dirty helper is required for
proper dirty/damage processing. The drm/msm driver requires that to
function to let CMD panels to work. Use simplified version of
drm_fbdev_generic_helper_fb_dirty() to fix support for CMD mode panels.
Reported-by: Degdag Mohamed <degdagmohamed@xxxxxxxxx>
Fixes: 93e81e38e197 ("drm/fb_helper: Minimize damage-helper overhead")
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
To make mmap work correctly, you'll also need deferred I/O in the fbdev
code. AFAICT the driver never supported that.
We do not use the deferred I/O. The damage/dirty tracking is used to
check whether we should ping the CMD panel or not. See [1]
[1] https://lore.kernel.org/all/20220223191118.881321-1-robdclark@xxxxxxxxx/
Best regards
Thomas
---
drivers/gpu/drm/msm/msm_fbdev.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/gpu/drm/msm/msm_fbdev.c
b/drivers/gpu/drm/msm/msm_fbdev.c
index fa9c1cbffae3..b933a85420f6 100644
--- a/drivers/gpu/drm/msm/msm_fbdev.c
+++ b/drivers/gpu/drm/msm/msm_fbdev.c
@@ -139,8 +139,28 @@ static int msm_fbdev_create(struct drm_fb_helper
*helper,
return ret;
}
+static int msm_fbdev_fb_dirty(struct drm_fb_helper *helper,
+ struct drm_clip_rect *clip)
+{
+ struct drm_device *dev = helper->dev;
+ int ret;
+
+ /* Call damage handlers only if necessary */
+ if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
+ return 0;
+
+ if (helper->fb->funcs->dirty) {
+ ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
+ if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n",
ret))
+ return ret;
+ }
+
+ return 0;
+}
+
static const struct drm_fb_helper_funcs msm_fb_helper_funcs = {
.fb_probe = msm_fbdev_create,
+ .fb_dirty = msm_fbdev_fb_dirty,
};
/*
--
With best wishes
Dmitry
