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 <[email protected]>
---
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
-
+ }
return ret;
}
EXPORT_SYMBOL(drm_bridge_attach);
--
2.33.0
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 <[email protected]>
> ---
> 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.
> return ret;
> }
> EXPORT_SYMBOL(drm_bridge_attach);
--
Regards,
Laurent Pinchart
Hi,
On Tue, Oct 12, 2021 at 10:08:28PM +0200, Sam Ravnborg wrote:
> Hi Guido,
>
> On Tue, Oct 12, 2021 at 09:58:58PM +0200, Guido G?nther 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 G?nther <[email protected]>
> > ---
> > 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);
>
> It would be better to use drm_probe_err().
That's what i thought initially but since the rest here uses DRM_*
logging i stuck with it. Happy to change that though.
Cheers,
-- Guido
>
> Sam
>
> > #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
> > -
> > + }
> > return ret;
> > }
> > EXPORT_SYMBOL(drm_bridge_attach);
> > --
> > 2.33.0
>
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 G?nther 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 G?nther <[email protected]>
> > ---
> > 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?
Cheers,
-- Guido
>
> > return ret;
> > }
> > EXPORT_SYMBOL(drm_bridge_attach);
>
> --
> Regards,
>
> Laurent Pinchart
>
Hi,
On Tue, Oct 12, 2021 at 10:47:14PM +0200, Guido G?nther 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 G?nther 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 G?nther <[email protected]>
> > > ---
> > > 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?
I should add that mxsfb does a `dev_err_probe()` already when checking
the return value of `drm_bridge_attach()` so the error printed is
triggered by the additional check added in the above function while the
code path already ignored -EPROBE_DEFER before. This looks sensible to
me since upper layers can't known when all the downstream bridges are
done probing or am I missing something?
Cheers,
-- Guido
>
> Cheers,
> -- Guido
>
> >
> > > return ret;
> > > }
> > > EXPORT_SYMBOL(drm_bridge_attach);
> >
> > --
> > Regards,
> >
> > Laurent Pinchart
> >
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 <[email protected]>
>>> ---
>>> 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
>>
Hi,
On Wed, Oct 13, 2021 at 08:48:32AM +0200, Andrzej Hajda wrote:
> On 12.10.2021 22:47, Guido G?nther 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 G?nther 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 G?nther <[email protected]>
> > > > ---
> > > > 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).
That helps, I'll look at that. Thanks!
-- Guido
>
> Regards
> Andrzej
>
>
> >
> > Cheers,
> > -- Guido
> >
> > >
> > > > return ret;
> > > > }
> > > > EXPORT_SYMBOL(drm_bridge_attach);
> > >
> > > --
> > > Regards,
> > >
> > > Laurent Pinchart
> > >
>
Hi Sam,
On Thu, Oct 14, 2021 at 09:35:20PM +0200, Sam Ravnborg wrote:
> Hi Guido,
>
> > > >
> > > > + 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);
> > >
> > > It would be better to use drm_probe_err().
> >
> > That's what i thought initially but since the rest here uses DRM_*
> > logging i stuck with it. Happy to change that though.
>
> If we continue to use the deprecated DRM_ logging functions then we will
> never get rid of them. And then I like the simplicity of
> drm_probe_err().
I wasn't aware those are deprecated. I'll fix that up in case this patch
is needed, which
https://lore.kernel.org/dri-devel/CAMty3ZAsn4K0WFRC_FNN2Mina0gSu4Nc1y1zVsoZ8GuSqcQFsA@mail.gmail.com/
makes it a bit look like it.
Cheers,
-- Guido
>
> In the end it is up to you.
>
> Sam
>