[Intel-gfx] [PATCH 4/8] drm/i915: Move Displayport test request and sink IRQ logic to intel_dp_detect()

[Paulo Zanoni]

2015-04-20 19:27 GMT-03:00 Todd Previte <tprevite at gmail.com>:
> Due to changes in the driver and to support Displayport compliance testing,
> the test request and sink IRQ logic has been relocated from
> intel_dp_check_link_status to intel_dp_detect. This is because the bulk of the
> compliance tests that set the TEST_REQUEST bit in the DEVICE_IRQ field of the
> DPCD issue a long pulse / hot plug event to signify the start of the test.
> Currently, for a long pulse, intel_dp_check_link_status is not called for a
> long HPD pulse, so if test requests come in, they cannot be detected by the
> driver.
>
> Once located in the intel_dp_detect, in the regular hot plug event path,
> proper detection of Displayport compliance test requests occurs which then
> invokes the test handler to support them. Additionally, this places compliance
> testing in the normal operational paths, eliminating as much special case code
> as possible.
>
> The only change in intel_dp_check_link_status with this patch is that when
> the IRQ is the result of a test request from the sink, the test handler is not
> invoked during the short pulse path. Short pulse test requests are for a
> particular variety of tests (mainly link training) that will be implemented
> in the future. Once those tests are available, the test request handler will
> be called from here as well.
>
> V1:
> - Rewored the commit message to be more clear about the content and intent
>   of this patch
> - Restore IRQ detection logic to intel_dp_check_link_status(). Continue to
>   detect and clear sink IRQs in the short pulse case. Ignore test requests
>   in the short pulses for now since they are for future test implementations.

It took me a a while to realize the "duplicate" code paths are not
really duplicate because of the short vs long thing. But this looks
correct so: Reviewed-by: Paulo Zanoni <paulo.r.zanoni at intel.com>

But, later, we could certainly use a cleanup on intel_dp_hpd_pulse().

>
> Signed-off-by: Todd Previte <tprevite at gmail.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 2ef05d7..b249ee8 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -4156,7 +4156,7 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
>                                    sink_irq_vector);
>
>                 if (sink_irq_vector & DP_AUTOMATED_TEST_REQUEST)
> -                       intel_dp_handle_test_request(intel_dp);
> +                       DRM_DEBUG_DRIVER("Test request in short pulse not handled\n");
>                 if (sink_irq_vector & (DP_CP_IRQ | DP_SINK_SPECIFIC_IRQ))
>                         DRM_DEBUG_DRIVER("CP or sink specific irq unhandled\n");
>         }
> @@ -4386,6 +4386,7 @@ intel_dp_detect(struct drm_connector *connector, bool force)
>         enum drm_connector_status status;
>         enum intel_display_power_domain power_domain;
>         bool ret;
> +       u8 sink_irq_vector;
>
>         DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
>                       connector->base.id, connector->name);
> @@ -4428,6 +4429,20 @@ intel_dp_detect(struct drm_connector *connector, bool force)
>                 intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
>         status = connector_status_connected;
>
> +       /* 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)) {
> +               /* Clear interrupt source */
> +               drm_dp_dpcd_writeb(&intel_dp->aux,
> +                                  DP_DEVICE_SERVICE_IRQ_VECTOR,
> +                                  sink_irq_vector);
> +
> +               if (sink_irq_vector & DP_AUTOMATED_TEST_REQUEST)
> +                       intel_dp_handle_test_request(intel_dp);
> +               if (sink_irq_vector & (DP_CP_IRQ | DP_SINK_SPECIFIC_IRQ))
> +                       DRM_DEBUG_DRIVER("CP or sink specific irq unhandled\n");
> +       }
> +
>  out:
>         intel_dp_power_put(intel_dp, power_domain);
>         return status;
> --
> 1.9.1
>
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-- 
Paulo Zanoni