drm/i915: Don't check gmch state on inherited configs

commit 9953599bc02dbc1d3330e6a0bfc6c50e9dffcac6 upstream.

... our current modeset code isn't good enough yet to handle this. The
scenario is:

1. BIOS sets up a cloned config with lvds+external screen on the same
pipe, e.g. pipe B.

2. We read out that state for pipe B and assign the gmch_pfit state to
it.

3. The initial modeset switches the lvds to pipe A but due to lack of
atomic modeset we don't recompute the config of pipe B.

-> both pipes now claim (in the sw pipe config structure) to use the
gmch_pfit, which just won't work.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=74081
Tested-by: max <manikulin@gmail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 963639d..84629d4 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9354,11 +9354,22 @@ intel_pipe_config_compare(struct drm_device *dev,
        PIPE_CONF_CHECK_I(pipe_src_w);
        PIPE_CONF_CHECK_I(pipe_src_h);
 
-       PIPE_CONF_CHECK_I(gmch_pfit.control);
-       /* pfit ratios are autocomputed by the hw on gen4+ */
-       if (INTEL_INFO(dev)->gen < 4)
-               PIPE_CONF_CHECK_I(gmch_pfit.pgm_ratios);
-       PIPE_CONF_CHECK_I(gmch_pfit.lvds_border_bits);
+       /*
+        * FIXME: BIOS likes to set up a cloned config with lvds+external
+        * screen. Since we don't yet re-compute the pipe config when moving
+        * just the lvds port away to another pipe the sw tracking won't match.
+        *
+        * Proper atomic modesets with recomputed global state will fix this.
+        * Until then just don't check gmch state for inherited modes.
+        */
+       if (!PIPE_CONF_QUIRK(PIPE_CONFIG_QUIRK_INHERITED_MODE)) {
+               PIPE_CONF_CHECK_I(gmch_pfit.control);
+               /* pfit ratios are autocomputed by the hw on gen4+ */
+               if (INTEL_INFO(dev)->gen < 4)
+                       PIPE_CONF_CHECK_I(gmch_pfit.pgm_ratios);
+               PIPE_CONF_CHECK_I(gmch_pfit.lvds_border_bits);
+       }
+
        PIPE_CONF_CHECK_I(pch_pfit.enabled);
        if (current_config->pch_pfit.enabled) {
                PIPE_CONF_CHECK_I(pch_pfit.pos);
@@ -11193,6 +11204,8 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
                            base.head) {
                memset(&crtc->config, 0, sizeof(crtc->config));
 
+               crtc->config.quirks |= PIPE_CONFIG_QUIRK_INHERITED_MODE;
+
                crtc->active = dev_priv->display.get_pipe_config(crtc,
                                                                 &crtc->config);
 

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index fbfaaba..00de120 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -219,7 +219,8 @@ struct intel_crtc_config {
         * tracked with quirk flags so that fastboot and state checker can act
         * accordingly.
         */
-#define PIPE_CONFIG_QUIRK_MODE_SYNC_FLAGS (1<<0) /* unreliable sync mode.flags */
+#define PIPE_CONFIG_QUIRK_MODE_SYNC_FLAGS      (1<<0) /* unreliable sync mode.flags */
+#define PIPE_CONFIG_QUIRK_INHERITED_MODE       (1<<1) /* mode inherited from firmware */
        unsigned long quirks;
 
        /* User requested mode, only valid as a starting point to