[Intel-gfx] [PATCH] drm/i915: Fix all pipe->plane mappings before sanitizing crtc

[Ander Conselvan de Oliveira]

On 01/14/2015 12:47 PM, Jani Nikula wrote:
> On Tue, 13 Jan 2015, Ander Conselvan de Oliveira <ander.conselvan.de.oliveira at intel.com> wrote:
>> If QUIRK_PIPEA_FORCE is necessary, intel_sanitize_crtc() might trigger
>> a mode set. In that case, if pipe A is disabled and pipe B is mapped to
>> plane B, that mode set happens before the mapping is fixed. Due to the
>> wrong state, the call to disable pipe B disables plane A (which is
>> already disabled) and later an assertion for plane B being enabled
>> (while it should have been disabled) is triggered.
>>
>> References: https://bugs.freedesktop.org/show_bug.cgi?id=72782
>
> If the patch is expected to fix the bug, please use Bugzilla:. If you're
> referencing a bug because it's otherwise relevant, please use
> References:.
>
> Which one is this?

This showed up in the dmesg attached to the referenced bug, but is not 
the root cause of the reported problem. As far as I know, there is no 
open bug for this particular issue.

Ander

>
> BR,
> Jani.
>
>
>> Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira at intel.com>
>> ---
>>   drivers/gpu/drm/i915/intel_display.c | 50 +++++++++++++++++++++++-------------
>>   1 file changed, 32 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index d01db1b..cf87528 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -13127,30 +13127,22 @@ intel_check_plane_mapping(struct intel_crtc *crtc)
>>   	return true;
>>   }
>>
>> -static void intel_sanitize_crtc(struct intel_crtc *crtc)
>> +static void intel_fix_plane_mapping(struct drm_device *dev)
>>   {
>> -	struct drm_device *dev = crtc->base.dev;
>> -	struct drm_i915_private *dev_priv = dev->dev_private;
>> -	u32 reg;
>> -
>> -	/* Clear any frame start delays used for debugging left by the BIOS */
>> -	reg = PIPECONF(crtc->config.cpu_transcoder);
>> -	I915_WRITE(reg, I915_READ(reg) & ~PIPECONF_FRAME_START_DELAY_MASK);
>> +	struct drm_i915_private *dev_priv = to_i915(dev);
>> +	struct intel_crtc *crtc;
>>
>> -	/* restore vblank interrupts to correct state */
>> -	if (crtc->active) {
>> -		update_scanline_offset(crtc);
>> -		drm_vblank_on(dev, crtc->pipe);
>> -	} else
>> -		drm_vblank_off(dev, crtc->pipe);
>> +	/* gen4+ has a fixed plane -> pipe mapping.*/
>> +	if (INTEL_INFO(dev)->gen >= 4)
>> +		return;
>>
>> -	/* We need to sanitize the plane -> pipe mapping first because this will
>> -	 * disable the crtc (and hence change the state) if it is wrong. Note
>> -	 * that gen4+ has a fixed plane -> pipe mapping.  */
>> -	if (INTEL_INFO(dev)->gen < 4 && !intel_check_plane_mapping(crtc)) {
>> +	for_each_intel_crtc(dev, crtc) {
>>   		struct intel_connector *connector;
>>   		bool plane;
>>
>> +		if (intel_check_plane_mapping(crtc))
>> +			continue;
>> +
>>   		DRM_DEBUG_KMS("[CRTC:%d] wrong plane connection detected!\n",
>>   			      crtc->base.base.id);
>>
>> @@ -13184,6 +13176,24 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc)
>>   		WARN_ON(crtc->active);
>>   		crtc->base.enabled = false;
>>   	}
>> +}
>> +
>> +static void intel_sanitize_crtc(struct intel_crtc *crtc)
>> +{
>> +	struct drm_device *dev = crtc->base.dev;
>> +	struct drm_i915_private *dev_priv = dev->dev_private;
>> +	u32 reg;
>> +
>> +	/* Clear any frame start delays used for debugging left by the BIOS */
>> +	reg = PIPECONF(crtc->config.cpu_transcoder);
>> +	I915_WRITE(reg, I915_READ(reg) & ~PIPECONF_FRAME_START_DELAY_MASK);
>> +
>> +	/* restore vblank interrupts to correct state */
>> +	if (crtc->active) {
>> +		update_scanline_offset(crtc);
>> +		drm_vblank_on(dev, crtc->pipe);
>> +	} else
>> +		drm_vblank_off(dev, crtc->pipe);
>>
>>   	if (dev_priv->quirks & QUIRK_PIPEA_FORCE &&
>>   	    crtc->pipe == PIPE_A && !crtc->active) {
>> @@ -13442,6 +13452,10 @@ void intel_modeset_setup_hw_state(struct drm_device *dev,
>>   		intel_sanitize_encoder(encoder);
>>   	}
>>
>> +	/* We need to sanitize the plane -> pipe mapping first because this will
>> +	 * disable the crtc (and hence change the state) if it is wrong. */
>> +	intel_fix_plane_mapping(dev);
>> +
>>   	for_each_pipe(dev_priv, pipe) {
>>   		crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
>>   		intel_sanitize_crtc(crtc);
>> --
>> 1.9.1
>>
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>