[Intel-gfx] [PATCH] drm/i915/icl: fix transcoder state readout

[Jani Nikula]

On Tue, 04 Dec 2018, Imre Deak <imre.deak at intel.com> wrote:
> On Tue, Dec 04, 2018 at 12:19:26PM +0200, Jani Nikula wrote:
>> Commit 2ca711caeca2 ("drm/i915/icl: Consider DSI for getting transcoder
>> state") clobbers the previously read TRANS_DDI_FUNC_CTL_EDP register
>> contents with TRANS_DDI_FUNC_CTL_DSI0 contents. Fix the state readout,
>> and handle DSI 1 while at it.
>> 
>> Use a bitmask for iterating and logging transcoders, because the allowed
>> combinations are a bit funky.
>> 
>> Fixes: 2ca711caeca2 ("drm/i915/icl: Consider DSI for getting transcoder state")
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108928
>
>> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
>> Cc: Madhav Chauhan <madhav.chauhan at intel.com>
>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_display.c | 48 ++++++++++++++++++++----------------
>>  1 file changed, 27 insertions(+), 21 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index a2584f977ab1..64b0ecd538fd 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -9476,13 +9476,18 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
>>  	struct drm_device *dev = crtc->base.dev;
>>  	struct drm_i915_private *dev_priv = to_i915(dev);
>>  	enum intel_display_power_domain power_domain;
>> +	unsigned long panel_transcoder_mask = BIT(TRANSCODER_EDP);
>> +	unsigned long enabled_panel_transcoders = 0;
>> +	enum transcoder panel_transcoder;
>>  	u32 tmp;
>> -	bool is_dsi = false;
>> -	bool is_edp = false;
>> +
>> +	if (IS_ICELAKE(dev_priv))
>> +		panel_transcoder_mask |=
>> +			BIT(TRANSCODER_DSI_0) | BIT(TRANSCODER_DSI_1);
>>  
>>  	/*
>>  	 * The pipe->transcoder mapping is fixed with the exception of the eDP
>> -	 * transcoder handled below.
>> +	 * and DSI transcoders handled below.
>>  	 */
>>  	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
>>  
>> @@ -9490,23 +9495,22 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
>>  	 * XXX: Do intel_display_power_get_if_enabled before reading this (for
>>  	 * consistency and less surprising code; it's in always on power).
>>  	 */
>> -	tmp = I915_READ(TRANS_DDI_FUNC_CTL(TRANSCODER_EDP));
>> -	if (tmp & TRANS_DDI_FUNC_ENABLE)
>> -		is_edp = true;
>> +	for_each_set_bit(panel_transcoder, &panel_transcoder_mask, 32) {
>
> nit: BITS_PER_LONG or I915_MAX_TRANSCODERS?
>
>> +		enum pipe trans_pipe;
>>  
>> -	if (IS_ICELAKE(dev_priv)) {
>> -		tmp = I915_READ(TRANS_DDI_FUNC_CTL(TRANSCODER_DSI_0));
>> -		if (tmp & TRANS_DDI_FUNC_ENABLE)
>> -			is_dsi = true;
>> -	}
>> +		tmp = I915_READ(TRANS_DDI_FUNC_CTL(panel_transcoder));
>> +		if (!(tmp & TRANS_DDI_FUNC_ENABLE))
>> +			continue;
>>  
>> -	WARN_ON(is_edp && is_dsi);
>> +		/* Log all enabled ones, only use the first one */
>> +		enabled_panel_transcoders |= BIT(panel_transcoder);
>> +		if (enabled_panel_transcoders != BIT(panel_transcoder))
>> +			continue;
>
>
> nit: As you explained for DSI dual mode both transcoders are needed and
> we don't support atm two separate DSI ports. A code comment about this
> would be nice. Maybe for the two DSI port case we should also warn below.
>
> With or without the nits:
> Reviewed-by: Imre Deak <imre.deak at intel.com>

Thanks, pushed with the comment added.

BR,
Jani.

>
>>  
>> -	if (is_edp || is_dsi) {
>> -		enum pipe trans_pipe;
>>  		switch (tmp & TRANS_DDI_EDP_INPUT_MASK) {
>>  		default:
>> -			WARN(1, "unknown pipe linked to edp transcoder\n");
>> +			WARN(1, "unknown pipe linked to transcoder %s\n",
>> +			     transcoder_name(panel_transcoder));
>>  			/* fall through */
>>  		case TRANS_DDI_EDP_INPUT_A_ONOFF:
>>  		case TRANS_DDI_EDP_INPUT_A_ON:
>> @@ -9520,14 +9524,16 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc,
>>  			break;
>>  		}
>>  
>> -		if (trans_pipe == crtc->pipe) {
>> -			if (is_edp)
>> -				pipe_config->cpu_transcoder = TRANSCODER_EDP;
>> -			else if (is_dsi)
>> -				pipe_config->cpu_transcoder = TRANSCODER_DSI_0;
>> -		}
>> +		if (trans_pipe == crtc->pipe)
>> +			pipe_config->cpu_transcoder = panel_transcoder;
>>  	}
>>  
>> +	/*
>> +	 * Valid combos: none, eDP, DSI0, DSI1, DSI0+DSI1
>> +	 */
>> +	WARN_ON((enabled_panel_transcoders & BIT(TRANSCODER_EDP)) &&
>> +		enabled_panel_transcoders != BIT(TRANSCODER_EDP));
>> +
>>  	power_domain = POWER_DOMAIN_TRANSCODER(pipe_config->cpu_transcoder);
>>  	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
>>  		return false;
>> -- 
>> 2.11.0
>> 
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-- 
Jani Nikula, Intel Open Source Graphics Center