[Intel-gfx] [PATCH] drm/i915: disable cloning on sdvo

[Paulo Zanoni]

Hi

2012/11/16 Daniel Vetter <daniel at ffwll.ch>:
> On Fri, Nov 16, 2012 at 12:04:35PM -0200, Paulo Zanoni wrote:
>> Hi
>>
>> 2012/11/13 Daniel Vetter <daniel.vetter at ffwll.ch>:
>> > After the recent pile of disable-cloning patches, e.g.
>> >
>> > commit e3b86d6941c7e5f90be05d986fce1fcb40c68d6b
>> > Author: Egbert Eich <eich at suse.de>
>> > Date:   Sat Oct 13 14:30:15 2012 +0200
>> >
>> >     DRM/i915: Don't clone SDVO LVDS with analog
>> >
>> > and a bug report from Chris Wilson indicating that cloning doesn't
>> > even work for DVI-SDVO and native VGA, let's just disable cloning on
>> > sdvo encoders completely.
>> >
>> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29259
>> > Tested-by: Chris Wilson <chris at chris-wilson.co.uk>
>> > Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>> > ---
>> >  drivers/gpu/drm/i915/intel_sdvo.c |   12 +++++-------
>> >  1 file changed, 5 insertions(+), 7 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
>> > index d6a5fb9..909d34f 100644
>> > --- a/drivers/gpu/drm/i915/intel_sdvo.c
>> > +++ b/drivers/gpu/drm/i915/intel_sdvo.c
>> > @@ -2208,7 +2208,6 @@ intel_sdvo_dvi_init(struct intel_sdvo *intel_sdvo, int device)
>> >                 connector->connector_type = DRM_MODE_CONNECTOR_HDMIA;
>> >                 intel_sdvo->is_hdmi = true;
>> >         }
>> > -       intel_sdvo->base.cloneable = true;
>> >
>> >         intel_sdvo_connector_init(intel_sdvo_connector, intel_sdvo);
>> >         if (intel_sdvo->is_hdmi)
>> > @@ -2239,7 +2238,6 @@ intel_sdvo_tv_init(struct intel_sdvo *intel_sdvo, int type)
>> >
>> >         intel_sdvo->is_tv = true;
>> >         intel_sdvo->base.needs_tv_clock = true;
>> > -       intel_sdvo->base.cloneable = false;
>> >
>> >         intel_sdvo_connector_init(intel_sdvo_connector, intel_sdvo);
>> >
>> > @@ -2282,8 +2280,6 @@ intel_sdvo_analog_init(struct intel_sdvo *intel_sdvo, int device)
>> >                 intel_sdvo_connector->output_flag = SDVO_OUTPUT_RGB1;
>> >         }
>> >
>> > -       intel_sdvo->base.cloneable = true;
>> > -
>> >         intel_sdvo_connector_init(intel_sdvo_connector,
>> >                                   intel_sdvo);
>> >         return true;
>> > @@ -2314,9 +2310,6 @@ intel_sdvo_lvds_init(struct intel_sdvo *intel_sdvo, int device)
>> >                 intel_sdvo_connector->output_flag = SDVO_OUTPUT_LVDS1;
>> >         }
>> >
>> > -       /* SDVO LVDS is not cloneable because the input mode gets adjusted by the encoder */
>> > -       intel_sdvo->base.cloneable = false;
>> > -
>> >         intel_sdvo_connector_init(intel_sdvo_connector, intel_sdvo);
>> >         if (!intel_sdvo_create_enhance_property(intel_sdvo, intel_sdvo_connector))
>> >                 goto err;
>> > @@ -2726,6 +2719,11 @@ bool intel_sdvo_init(struct drm_device *dev, uint32_t sdvo_reg, bool is_sdvob)
>> >                 goto err_output;
>> >         }
>> >
>> > +       /* SDVO because we need different clocks for SDVO encoders compared to
>> > +        * VGA. And the sdvo encoder is also allowed to adjust the mode. So just
>> > +        * give up and disable it. */
>>
>> The code looks good, but the comment above is quite confusing. "SDVO because"?
>
> Oops. What about:
>
> "Cloning SDVO with anything is often impossible, since the SDVO encoder
> can request a special input timing mode. And even if that's not the case
> we have evidence that cloning a plain unscaled mode with VGA doesn't
> really work. Furthermore the cloning flags are way to simplistic anyway to

s/way to simplistic/way too simplistic/ ?

> express such constraints, so just give up on cloning for SDVO encoders."
>
> Is that good enough for a full r-b?

Yes. A simple "this doesn't work, maybe our code is bugged, maybe not,
so disable it anyway" would also have done the job :)

Reviewed-by: Paulo Zanoni <paulo.r.zanoni at intel.com>

>
> Yours, Daniel
>
>>
>> > +       intel_sdvo->base.cloneable = false;
>> > +
>> >         /* Only enable the hotplug irq if we need it, to work around noisy
>> >          * hotplug lines.
>> >          */
>> > --
>> > 1.7.10.4
>> >
>> > _______________________________________________
>> > Intel-gfx mailing list
>> > Intel-gfx at lists.freedesktop.org
>> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>>
>>
>>
>> --
>> Paulo Zanoni
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch



-- 
Paulo Zanoni