On 12.10.2021 22:47, Guido Günther wrote:
Hi Laurent,
On Tue, Oct 12, 2021 at 11:17:07PM +0300, Laurent Pinchart wrote:
Hi Guido,
Thank you for the patch.
On Tue, Oct 12, 2021 at 09:58:58PM +0200, Guido Günther wrote:
Otherwise logs are filled with
[drm:drm_bridge_attach] *ERROR* failed to attach bridge /soc@0/bus@30800000/mipi-dsi@30a0 0000 to encoder None-34: -517
when the bridge isn't ready yet.
Fixes: fb8d617f8fd6 ("drm/bridge: Centralize error message when bridge attach fails")
Signed-off-by: Guido Günther <agx@xxxxxxxxxxx>
---
drivers/gpu/drm/drm_bridge.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index a8ed66751c2d..f0508e85ae98 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -227,14 +227,15 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
bridge->encoder = NULL;
list_del(&bridge->chain_node);
+ if (ret != -EPROBE_DEFER) {
#ifdef CONFIG_OF
- DRM_ERROR("failed to attach bridge %pOF to encoder %s: %d\n",
- bridge->of_node, encoder->name, ret);
+ DRM_ERROR("failed to attach bridge %pOF to encoder %s: %d\n",
+ bridge->of_node, encoder->name, ret);
#else
- DRM_ERROR("failed to attach bridge to encoder %s: %d\n",
- encoder->name, ret);
+ DRM_ERROR("failed to attach bridge to encoder %s: %d\n",
+ encoder->name, ret);
#endif
-
+ }
This looks fine as such, but I'm concerned about the direction it's
taking. Ideally, probe deferral should happen at probe time, way before
the bridge is attached. Doing otherwise is a step in the wrong direction
in my opinion, and something we'll end up regretting when we'll feel the
pain it inflicts.
The particular case I'm seeing this is the nwl driver probe deferrals if
the panel bridge isn't ready (which needs a bunch of components
(dsi, panel, backlight wrapped led, ...) and it probes fine later on so I
wonder where you see the actual error cause? That downstream of the
bridge isn't ready or that the display controller is already attaching
the bridge?
So it is something wrong there, nwl should not publish bridge interface
until it gather its resources (the panel in this case).
Regards
Andrzej
Cheers,
-- Guido
return ret;
}
EXPORT_SYMBOL(drm_bridge_attach);
--
Regards,
Laurent Pinchart
