Re: [Intel-gfx] [PATCH v2 7/8] drm/i915/tc: Catch TC users accessing FIA registers without enable aux

From: Imre Deak <imre.deak@intel.com>
To: "José Roberto de Souza" <jose.souza@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH v2 7/8] drm/i915/tc: Catch TC users accessing FIA registers without enable aux
Date: Tue, 7 Apr 2020 19:04:55 +0300	[thread overview]
Message-ID: <20200407160455.GG21484@ideak-desk.fi.intel.com> (raw)
In-Reply-To: <20200407011157.362092-7-jose.souza@intel.com>

On Mon, Apr 06, 2020 at 06:11:56PM -0700, José Roberto de Souza wrote:
> As described in "drm/i915/tc/icl: Implement TC cold sequences" users
> of TC functions should held aux power well during access to avoid
> read garbage due HW in TC cold state.
> 
> Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_tc.c | 22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index 83861653768d..e473bb4a9b0b 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -95,6 +95,20 @@ tc_cold_unblock(struct intel_digital_port *dig_port, intel_wakeref_t wakeref)
>  	intel_display_power_put_async(i915, domain, wakeref);
>  }
>  
> +static void
> +is_tc_cold_blocked(struct intel_digital_port *dig_port)

assert_tc_cold_blocked()?

Reviewed-by: Imre Deak <imre.deak@intel.com>

> +{
> +	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> +	bool enabled;
> +
> +	if (INTEL_GEN(i915) == 11 && !dig_port->tc_legacy_port)
> +		return;
> +
> +	enabled = intel_display_power_is_enabled(i915,
> +						 tc_cold_get_power_domain(dig_port));
> +	drm_WARN_ON(&i915->drm, !enabled);
> +}
> +
>  u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port)
>  {
>  	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> @@ -104,7 +118,7 @@ u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port)
>  	lane_mask = intel_uncore_read(uncore,
>  				      PORT_TX_DFLEXDPSP(dig_port->tc_phy_fia));
>  
> -	drm_WARN_ON(&i915->drm, lane_mask == 0xffffffff);
> +	is_tc_cold_blocked(dig_port);
>  
>  	lane_mask &= DP_LANE_ASSIGNMENT_MASK(dig_port->tc_phy_fia_idx);
>  	return lane_mask >> DP_LANE_ASSIGNMENT_SHIFT(dig_port->tc_phy_fia_idx);
> @@ -119,7 +133,7 @@ u32 intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port)
>  	pin_mask = intel_uncore_read(uncore,
>  				     PORT_TX_DFLEXPA1(dig_port->tc_phy_fia));
>  
> -	drm_WARN_ON(&i915->drm, pin_mask == 0xffffffff);
> +	is_tc_cold_blocked(dig_port);
>  
>  	return (pin_mask & DP_PIN_ASSIGNMENT_MASK(dig_port->tc_phy_fia_idx)) >>
>  	       DP_PIN_ASSIGNMENT_SHIFT(dig_port->tc_phy_fia_idx);
> @@ -134,6 +148,8 @@ int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
>  	if (dig_port->tc_mode != TC_PORT_DP_ALT)
>  		return 4;
>  
> +	is_tc_cold_blocked(dig_port);
> +
>  	lane_mask = 0;
>  	with_intel_display_power(i915, POWER_DOMAIN_DISPLAY_CORE, wakeref)
>  		lane_mask = intel_tc_port_get_lane_mask(dig_port);
> @@ -166,6 +182,8 @@ void intel_tc_port_set_fia_lane_count(struct intel_digital_port *dig_port,
>  	drm_WARN_ON(&i915->drm,
>  		    lane_reversal && dig_port->tc_mode != TC_PORT_LEGACY);
>  
> +	is_tc_cold_blocked(dig_port);
> +
>  	val = intel_uncore_read(uncore,
>  				PORT_TX_DFLEXDPMLE1(dig_port->tc_phy_fia));
>  	val &= ~DFLEXDPMLE1_DPMLETC_MASK(dig_port->tc_phy_fia_idx);
> -- 
> 2.26.0
> 
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