From 6aa3bef15d6525198f584358055a4176eeca01af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Roberto=20de=20Souza?= <jose.souza@intel.com>
Date: Wed, 7 Aug 2019 17:49:34 -0700
Subject: drm/i915: Get transcoder power domain before reading its register
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Git-commit: 6aa3bef15d6525198f584358055a4176eeca01af
Patch-mainline: v5.4-rc1
References: bsc#1152489
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>
Link: https://patchwork.freedesktop.org/patch/msgid/20190808004935.1787-1-jose.souza@intel.com
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/i915/display/intel_ddi.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index bde9e0f61cef..8d4593ee5c09 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;
--
2.28.0