diff mbox series

[v2,1/2] drm/i915: Get transcoder power domain before reading its register

Message ID 20190802215356.13563-1-jose.souza@intel.com (mailing list archive)
State New, archived
Headers show
Series [v2,1/2] drm/i915: Get transcoder power domain before reading its register | expand

Commit Message

Souza, Jose Aug. 2, 2019, 9:53 p.m. UTC 
When getting the pipes attached to encoder if it is not a eDP encoder
it iterates over all pipes and read a transcoder register.
But it should not read a transcoder register before get its power
domain.

It was not a issue in gens older than 12 because if it only had
port A connected it would be attached to EDP and it would skip all
the transcoders readout, if it had more than one port connected,
pipe B would cause PG3 to be on and it contains all other
transcoders.

But on gen 12 there is no EDP transcoder so it is always iterating
over all pipes and if only one sink is connected, PG3 is kept off
and reading other transcoders registers would cause a
unclaimed read warning.

So here getting the power domain of the transcoder only if it is
enabled, otherwise it is not connected to the DDI.

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 8 ++++++++
 1 file changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index fb58845020dc..660bb001be35 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2015,6 +2015,12 @@  static void intel_ddi_get_encoder_pipes(struct intel_encoder *encoder,
 	for_each_pipe(dev_priv, p) {
 		enum transcoder cpu_transcoder = (enum transcoder)p;
 		unsigned int port_mask, ddi_select;
+		intel_wakeref_t trans_wakeref;
+
+		trans_wakeref = intel_display_power_get_if_enabled(dev_priv,
+								   POWER_DOMAIN_TRANSCODER(cpu_transcoder));
+		if (!trans_wakeref)
+			continue;
 
 		if (INTEL_GEN(dev_priv) >= 12) {
 			port_mask = TGL_TRANS_DDI_PORT_MASK;
@@ -2025,6 +2031,8 @@  static void intel_ddi_get_encoder_pipes(struct intel_encoder *encoder,
 		}
 
 		tmp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
+		intel_display_power_put(dev_priv, POWER_DOMAIN_TRANSCODER(cpu_transcoder),
+					trans_wakeref);
 
 		if ((tmp & port_mask) != ddi_select)
 			continue;