Hi Jani,

On 05.05.2022 20:37, Jani Nikula wrote:
On Wed, 04 May 2022, Andrzej Hajda <andrzej.ha...@intel.com> wrote:
On some configurations drm_fb_helper_initial_config sometimes fails.
Logging error value should help debugging such issues.

Signed-off-by: Andrzej Hajda <andrzej.ha...@intel.com>
---
  drivers/gpu/drm/i915/display/intel_fbdev.c | 11 ++++++++---
  1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c 
b/drivers/gpu/drm/i915/display/intel_fbdev.c
index 221336178991f0..557c7f15ac22a9 100644
--- a/drivers/gpu/drm/i915/display/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
@@ -539,11 +539,16 @@ int intel_fbdev_init(struct drm_device *dev)
  static void intel_fbdev_initial_config(void *data, async_cookie_t cookie)
  {
        struct intel_fbdev *ifbdev = data;
+       int ret;
/* Due to peculiar init order wrt to hpd handling this is separate. */
-       if (drm_fb_helper_initial_config(&ifbdev->helper,
-                                        ifbdev->preferred_bpp))
-               intel_fbdev_unregister(to_i915(ifbdev->helper.dev));
+       ret = drm_fb_helper_initial_config(&ifbdev->helper,
+                                          ifbdev->preferred_bpp);
+       if (!ret)
+               return;
If this patch is intended for merging, I'd prefer keeping the failure
path indented within if (ret).

+       drm_err(ifbdev->helper.dev, "failed to set initial configuration: 
%pe\n",
+               ERR_PTR(ret));
I'm leaning towards preferring "%s", errname(ret) over "%pe",
ERR_PTR(ret) because everyone knows what %s means and using ERR_PTR()
seems odd when it's really a plain int.

BR,
Jani.

Apparently this patch didn't help in catching the bug, so no big feelings about it. Anyway I think I have found the issue I was looking for: hpd poll worker could be run during driver removal after console unregistration causing re-registration of console, which is not removed later leaving dangling pointers.
If you could take a look at the patch [1], it would be nice :)

[1]: https://patchwork.freedesktop.org/series/103621/#rev1

Regards
Andrzej


+       intel_fbdev_unregister(to_i915(ifbdev->helper.dev));
  }
void intel_fbdev_initial_config_async(struct drm_device *dev)

Reply via email to