[Intel-gfx] [PATCH 11/12] drm/i915: Don't try to ack sink irqs when there are none

[Daniel Vetter]

On Thu, Jul 28, 2016 at 05:50:47PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> My ASUS PB278 at least doesn't seem to appreciate when you try to
> ack sink irqs when there are none. Results in thus sort of dmesg spam
> [drm:drm_dp_dpcd_access] too many retries, giving up
> 
> Let's skip the ack if there are no pending irqs. I have no clue why we
> do this in two places. One of them likely should just go away. Oh, and
> MST has its own sink irq handler too...
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Yeah it's a mess still :( Change itself makes sense.

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  drivers/gpu/drm/i915/intel_dp.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 08d95352ffd6..7551d92a3cfb 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -3934,7 +3934,7 @@ intel_dp_link_retrain(struct intel_dp *intel_dp)
>  static bool
>  intel_dp_short_pulse(struct intel_dp *intel_dp)
>  {
> -	u8 sink_irq_vector;
> +	u8 sink_irq_vector = 0;
>  	u8 old_sink_count = intel_dp->sink_count;
>  	bool ret;
>  
> @@ -3961,7 +3961,8 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
>  
>  	/* Try to read the source of the interrupt */
>  	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
> -	    intel_dp_get_sink_irq(intel_dp, &sink_irq_vector)) {
> +	    intel_dp_get_sink_irq(intel_dp, &sink_irq_vector) &&
> +	    sink_irq_vector != 0) {
>  		/* Clear interrupt source */
>  		drm_dp_dpcd_writeb(&intel_dp->aux,
>  				   DP_DEVICE_SERVICE_IRQ_VECTOR,
> @@ -4227,7 +4228,7 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
>  	struct drm_device *dev = connector->dev;
>  	enum drm_connector_status status;
>  	enum intel_display_power_domain power_domain;
> -	u8 sink_irq_vector;
> +	u8 sink_irq_vector = 0;
>  
>  	power_domain = intel_display_port_aux_power_domain(intel_encoder);
>  	intel_display_power_get(to_i915(dev), power_domain);
> @@ -4292,7 +4293,8 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
>  
>  	/* Try to read the source of the interrupt */
>  	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
> -	    intel_dp_get_sink_irq(intel_dp, &sink_irq_vector)) {
> +	    intel_dp_get_sink_irq(intel_dp, &sink_irq_vector) &&
> +	    sink_irq_vector != 0) {
>  		/* Clear interrupt source */
>  		drm_dp_dpcd_writeb(&intel_dp->aux,
>  				   DP_DEVICE_SERVICE_IRQ_VECTOR,
> -- 
> 2.7.4
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch