drm/i915: Don't clobber crtc_state->cpu_transcoder for inactive crtcs

Inactive crtcs are supposed to have their crtc_state completely
cleared. Currently we are clobbering crtc_state->cpu_transcoder
before determining whether it's actually enabled or not. Don't
do that.

I want to rework the inherited flag handling for inactive crtcs
a bit, and having a bogus cpu_transcoder in the crtc state can
then cause confusing fastset mismatches even when the crtc never
changes state during the commit.

Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250306163420.3961-3-ville.syrjala@linux.intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 5c1c2cb..8d94ab7 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -2985,26 +2985,25 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
 {
        struct intel_display *display = to_intel_display(crtc);
        enum intel_display_power_domain power_domain;
+       enum transcoder cpu_transcoder = (enum transcoder)crtc->pipe;
        intel_wakeref_t wakeref;
+       bool ret = false;
        u32 tmp;
-       bool ret;
 
        power_domain = POWER_DOMAIN_PIPE(crtc->pipe);
        wakeref = intel_display_power_get_if_enabled(display, power_domain);
        if (!wakeref)
                return false;
 
-       pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
-       pipe_config->sink_format = pipe_config->output_format;
-       pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
-
-       ret = false;
-
-       tmp = intel_de_read(display,
-                           TRANSCONF(display, pipe_config->cpu_transcoder));
+       tmp = intel_de_read(display, TRANSCONF(display, cpu_transcoder));
        if (!(tmp & TRANSCONF_ENABLE))
                goto out;
 
+       pipe_config->cpu_transcoder = cpu_transcoder;
+
+       pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
+       pipe_config->sink_format = pipe_config->output_format;
+
        if (display->platform.g4x || display->platform.valleyview ||
            display->platform.cherryview) {
                switch (tmp & TRANSCONF_BPC_MASK) {
@@ -3328,23 +3327,22 @@ static bool ilk_get_pipe_config(struct intel_crtc *crtc,
 {
        struct intel_display *display = to_intel_display(crtc);
        enum intel_display_power_domain power_domain;
+       enum transcoder cpu_transcoder = (enum transcoder)crtc->pipe;
        intel_wakeref_t wakeref;
+       bool ret = false;
        u32 tmp;
-       bool ret;
 
        power_domain = POWER_DOMAIN_PIPE(crtc->pipe);
        wakeref = intel_display_power_get_if_enabled(display, power_domain);
        if (!wakeref)
                return false;
 
-       pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
-
-       ret = false;
-       tmp = intel_de_read(display,
-                           TRANSCONF(display, pipe_config->cpu_transcoder));
+       tmp = intel_de_read(display, TRANSCONF(display, cpu_transcoder));
        if (!(tmp & TRANSCONF_ENABLE))
                goto out;
 
+       pipe_config->cpu_transcoder = cpu_transcoder;
+
        switch (tmp & TRANSCONF_BPC_MASK) {
        case TRANSCONF_BPC_6:
                pipe_config->pipe_bpp = 18;