On Thu, Mar 10, 2022 at 12:05:17PM -0800, José Roberto de Souza wrote:
> Commit 13ea6db2cf24 ("drm/i915/edp: Ignore short pulse when panel
> powered off") completely broke short pulse handling for eDP as it is
> usually generated by sink when it is displaying image and there is
> some error or status that source needs to handle.
>
> When power panel is enabled, this state is enough to power aux
> transactions and VDD override is disabled, so intel_pps_have_power()
> is always returning false causing short pulses to be ignored.
I think the times that we use the vdd override should be
limited to:
- aux transfers while the display off
- potentially short periods of time during the modeset sequence
So I guess what you're saying here is that during those times
some panel is triggering an IRQ_HPD which, if ignored, causes
some problem for us?
>
> So here better naming this function that intends to check if aux
> lines are powered to avoid the endless cycle mentioned in the commit
> being fixed and fixing the check for what it is intended.
>
> Fixes: 13ea6db2cf24 ("drm/i915/edp: Ignore short pulse when panel powered
> off")
> Cc: Anshuman Gupta <anshuman.gu...@intel.com>
> Cc: Jani Nikula <jani.nik...@intel.com>
> Cc: Uma Shankar <uma.shan...@intel.com>
> Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
> Signed-off-by: José Roberto de Souza <jose.so...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
> drivers/gpu/drm/i915/display/intel_pps.c | 4 ++--
> drivers/gpu/drm/i915/display/intel_pps.h | 2 +-
> 3 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 619546441eae5..b029b064000d6 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4867,7 +4867,7 @@ intel_dp_hpd_pulse(struct intel_digital_port *dig_port,
> bool long_hpd)
> struct intel_dp *intel_dp = &dig_port->dp;
>
> if (dig_port->base.type == INTEL_OUTPUT_EDP &&
> - (long_hpd || !intel_pps_have_power(intel_dp))) {
> + (long_hpd || !intel_pps_have_vdd_power(intel_dp))) {
> /*
> * vdd off can generate a long/short pulse on eDP which
> * would require vdd on to handle it, and thus we
> diff --git a/drivers/gpu/drm/i915/display/intel_pps.c
> b/drivers/gpu/drm/i915/display/intel_pps.c
> index 9c986e8932f87..d3e6083ad5b79 100644
> --- a/drivers/gpu/drm/i915/display/intel_pps.c
> +++ b/drivers/gpu/drm/i915/display/intel_pps.c
> @@ -1075,13 +1075,13 @@ static void intel_pps_vdd_sanitize(struct intel_dp
> *intel_dp)
> edp_panel_vdd_schedule_off(intel_dp);
> }
>
> -bool intel_pps_have_power(struct intel_dp *intel_dp)
> +bool intel_pps_have_vdd_power(struct intel_dp *intel_dp)
> {
> intel_wakeref_t wakeref;
> bool have_power = false;
>
> with_intel_pps_lock(intel_dp, wakeref) {
> - have_power = edp_have_panel_power(intel_dp) &&
> + have_power = edp_have_panel_power(intel_dp) ||
> edp_have_panel_vdd(intel_dp);
> }
>
> diff --git a/drivers/gpu/drm/i915/display/intel_pps.h
> b/drivers/gpu/drm/i915/display/intel_pps.h
> index fbb47f6f453e4..948523ce32417 100644
> --- a/drivers/gpu/drm/i915/display/intel_pps.h
> +++ b/drivers/gpu/drm/i915/display/intel_pps.h
> @@ -37,7 +37,7 @@ void intel_pps_vdd_on(struct intel_dp *intel_dp);
> void intel_pps_on(struct intel_dp *intel_dp);
> void intel_pps_off(struct intel_dp *intel_dp);
> void intel_pps_vdd_off_sync(struct intel_dp *intel_dp);
> -bool intel_pps_have_power(struct intel_dp *intel_dp);
> +bool intel_pps_have_vdd_power(struct intel_dp *intel_dp);
> void intel_pps_wait_power_cycle(struct intel_dp *intel_dp);
>
> void intel_pps_init(struct intel_dp *intel_dp);
> --
> 2.35.1
--
Ville Syrjälä
Intel
