drm/i915: Pass down rc in intel_encoder->compute_config()

Something that I completely missed when implementing the new MST VCPI
atomic helpers is that with those helpers, there's technically a chance
of us having to grab additional modeset locks in ->compute_config() and
furthermore, that means we have the potential to hit a normal modeset
deadlock. However, because ->compute_config() only returns a bool this
means we can't return -EDEADLK when we need to drop locks and try again
which means we end up just failing the atomic check permanently. Whoops.

So, fix this by modifying ->compute_config() to pass down an actual
error code instead of a bool so that the atomic check can be restarted
on modeset deadlocks.

Thanks to Ville Syrjälä for pointing this out!

Changes since v1:
* Add some newlines
* Return only -EINVAL from hsw_crt_compute_config()
* Propogate return code from intel_dp_compute_dsc_params()
* Change all of the intel_dp_compute_link_config*() variants
* Don't miss if (hdmi_port_clock_valid()) branch in
  intel_hdmi_compute_config()

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: eceae1472467 ("drm/dp_mst: Start tracking per-port VCPI allocations")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109320
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190115200800.3121-1-lyude@redhat.com

13 files changed, 122 insertions, 112 deletions

diff --git a/drivers/gpu/drm/i915/icl_dsi.c b/drivers/gpu/drm/i915/icl_dsi.c
index 4dd793b78996..d9dcee4ec51f 100644
--- a/drivers/gpu/drm/i915/icl_dsi.c
+++ b/drivers/gpu/drm/i915/icl_dsi.c
@@ -1178,9 +1178,9 @@ static void gen11_dsi_get_config(struct intel_encoder *encoder,
         pipe_config->output_types |= BIT(INTEL_OUTPUT_DSI);
 }
 
-static bool gen11_dsi_compute_config(struct intel_encoder *encoder,
-                                     struct intel_crtc_state *pipe_config,
-                                     struct drm_connector_state *conn_state)
+static int gen11_dsi_compute_config(struct intel_encoder *encoder,
+                                    struct intel_crtc_state *pipe_config,
+                                    struct drm_connector_state *conn_state)
 {
         struct intel_dsi *intel_dsi = container_of(encoder, struct intel_dsi,
                                                    base);
@@ -1205,7 +1205,7 @@ static bool gen11_dsi_compute_config(struct intel_encoder *encoder,
         pipe_config->clock_set = true;
         pipe_config->port_clock = intel_dsi_bitrate(intel_dsi) / 5;
 
-        return true;
+        return 0;
 }
 
 static u64 gen11_dsi_get_power_domains(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 68f2fb89ece3..2e0fd9927db2 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -344,51 +344,52 @@ intel_crt_mode_valid(struct drm_connector *connector,
         return MODE_OK;
 }
 
-static bool intel_crt_compute_config(struct intel_encoder *encoder,
-                                     struct intel_crtc_state *pipe_config,
-                                     struct drm_connector_state *conn_state)
+static int intel_crt_compute_config(struct intel_encoder *encoder,
+                                    struct intel_crtc_state *pipe_config,
+                                    struct drm_connector_state *conn_state)
 {
         struct drm_display_mode *adjusted_mode =
                 &pipe_config->base.adjusted_mode;
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
-        return true;
+
+        return 0;
 }
 
-static bool pch_crt_compute_config(struct intel_encoder *encoder,
-                                   struct intel_crtc_state *pipe_config,
-                                   struct drm_connector_state *conn_state)
+static int pch_crt_compute_config(struct intel_encoder *encoder,
+                                  struct intel_crtc_state *pipe_config,
+                                  struct drm_connector_state *conn_state)
 {
         struct drm_display_mode *adjusted_mode =
                 &pipe_config->base.adjusted_mode;
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         pipe_config->has_pch_encoder = true;
         pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
 
-        return true;
+        return 0;
 }
 
-static bool hsw_crt_compute_config(struct intel_encoder *encoder,
-                                   struct intel_crtc_state *pipe_config,
-                                   struct drm_connector_state *conn_state)
+static int hsw_crt_compute_config(struct intel_encoder *encoder,
+                                  struct intel_crtc_state *pipe_config,
+                                  struct drm_connector_state *conn_state)
 {
         struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
         struct drm_display_mode *adjusted_mode =
                 &pipe_config->base.adjusted_mode;
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         /* HSW/BDW FDI limited to 4k */
         if (adjusted_mode->crtc_hdisplay > 4096 ||
             adjusted_mode->crtc_hblank_start > 4096)
-                return false;
+                return -EINVAL;
 
         pipe_config->has_pch_encoder = true;
         pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
@@ -397,7 +398,7 @@ static bool hsw_crt_compute_config(struct intel_encoder *encoder,
         if (HAS_PCH_LPT(dev_priv)) {
                 if (pipe_config->bw_constrained && pipe_config->pipe_bpp < 24) {
                         DRM_DEBUG_KMS("LPT only supports 24bpp\n");
-                        return false;
+                        return -EINVAL;
                 }
 
                 pipe_config->pipe_bpp = 24;
@@ -406,7 +407,7 @@ static bool hsw_crt_compute_config(struct intel_encoder *encoder,
         /* FDI must always be 2.7 GHz */
         pipe_config->port_clock = 135000 * 2;
 
-        return true;
+        return 0;
 }
 
 static bool intel_ironlake_crt_detect_hotplug(struct drm_connector *connector)
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index f3e1d6a0b7dd..fd06d1fd39d3 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -3875,9 +3875,9 @@ intel_ddi_compute_output_type(struct intel_encoder *encoder,
         }
 }
 
-static bool intel_ddi_compute_config(struct intel_encoder *encoder,
-                                     struct intel_crtc_state *pipe_config,
-                                     struct drm_connector_state *conn_state)
+static int intel_ddi_compute_config(struct intel_encoder *encoder,
+                                    struct intel_crtc_state *pipe_config,
+                                    struct drm_connector_state *conn_state)
 {
         struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
         enum port port = encoder->port;
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 20beb1977a27..52c63135bc65 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11517,10 +11517,13 @@ encoder_retry:
                         continue;
 
                 encoder = to_intel_encoder(connector_state->best_encoder);
-
-                if (!(encoder->compute_config(encoder, pipe_config, connector_state))) {
-                        DRM_DEBUG_KMS("Encoder config failure\n");
-                        return -EINVAL;
+                ret = encoder->compute_config(encoder, pipe_config,
+                                              connector_state);
+                if (ret < 0) {
+                        if (ret != -EDEADLK)
+                                DRM_DEBUG_KMS("Encoder config failure: %d\n",
+                                              ret);
+                        return ret;
                 }
         }
 
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index fdd2cbc56fa3..d18b72b5f0b8 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1808,7 +1808,7 @@ intel_dp_adjust_compliance_config(struct intel_dp *intel_dp,
 }
 
 /* Optimize link config in order: max bpp, min clock, min lanes */
-static bool
+static int
 intel_dp_compute_link_config_wide(struct intel_dp *intel_dp,
                                   struct intel_crtc_state *pipe_config,
                                   const struct link_config_limits *limits)
@@ -1834,17 +1834,17 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp,
                                         pipe_config->pipe_bpp = bpp;
                                         pipe_config->port_clock = link_clock;
 
-                                        return true;
+                                        return 0;
                                 }
                         }
                 }
         }
 
-        return false;
+        return -EINVAL;
 }
 
 /* Optimize link config in order: max bpp, min lanes, min clock */
-static bool
+static int
 intel_dp_compute_link_config_fast(struct intel_dp *intel_dp,
                                   struct intel_crtc_state *pipe_config,
                                   const struct link_config_limits *limits)
@@ -1870,13 +1870,13 @@ intel_dp_compute_link_config_fast(struct intel_dp *intel_dp,
                                         pipe_config->pipe_bpp = bpp;
                                         pipe_config->port_clock = link_clock;
 
-                                        return true;
+                                        return 0;
                                 }
                         }
                 }
         }
 
-        return false;
+        return -EINVAL;
 }
 
 static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc)
@@ -1894,19 +1894,20 @@ static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc)
         return 0;
 }
 
-static bool intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
-                                        struct intel_crtc_state *pipe_config,
-                                        struct drm_connector_state *conn_state,
-                                        struct link_config_limits *limits)
+static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
+                                       struct intel_crtc_state *pipe_config,
+                                       struct drm_connector_state *conn_state,
+                                       struct link_config_limits *limits)
 {
         struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
         struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
         struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
         u8 dsc_max_bpc;
         int pipe_bpp;
+        int ret;
 
         if (!intel_dp_supports_dsc(intel_dp, pipe_config))
-                return false;
+                return -EINVAL;
 
         dsc_max_bpc = min_t(u8, DP_DSC_MAX_SUPPORTED_BPC,
                             conn_state->max_requested_bpc);
@@ -1914,7 +1915,7 @@ static bool intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
         pipe_bpp = intel_dp_dsc_compute_bpp(intel_dp, dsc_max_bpc);
         if (pipe_bpp < DP_DSC_MIN_SUPPORTED_BPC * 3) {
                 DRM_DEBUG_KMS("No DSC support for less than 8bpc\n");
-                return false;
+                return -EINVAL;
         }
 
         /*
@@ -1948,7 +1949,7 @@ static bool intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
                                                      adjusted_mode->crtc_hdisplay);
                 if (!dsc_max_output_bpp || !dsc_dp_slice_count) {
                         DRM_DEBUG_KMS("Compressed BPP/Slice Count not supported\n");
-                        return false;
+                        return -EINVAL;
                 }
                 pipe_config->dsc_params.compressed_bpp = min_t(u16,
                                                                dsc_max_output_bpp >> 4,
@@ -1965,16 +1966,19 @@ static bool intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
                         pipe_config->dsc_params.dsc_split = true;
                 } else {
                         DRM_DEBUG_KMS("Cannot split stream to use 2 VDSC instances\n");
-                        return false;
+                        return -EINVAL;
                 }
         }
-        if (intel_dp_compute_dsc_params(intel_dp, pipe_config) < 0) {
+
+        ret = intel_dp_compute_dsc_params(intel_dp, pipe_config);
+        if (ret < 0) {
                 DRM_DEBUG_KMS("Cannot compute valid DSC parameters for Input Bpp = %d "
                               "Compressed BPP = %d\n",
                               pipe_config->pipe_bpp,
                               pipe_config->dsc_params.compressed_bpp);
-                return false;
+                return ret;
         }
+
         pipe_config->dsc_params.compression_enable = true;
         DRM_DEBUG_KMS("DP DSC computed with Input Bpp = %d "
                       "Compressed Bpp = %d Slice Count = %d\n",
@@ -1982,10 +1986,10 @@ static bool intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
                       pipe_config->dsc_params.compressed_bpp,
                       pipe_config->dsc_params.slice_count);
 
-        return true;
+        return 0;
 }
 
-static bool
+static int
 intel_dp_compute_link_config(struct intel_encoder *encoder,
                              struct intel_crtc_state *pipe_config,
                              struct drm_connector_state *conn_state)
@@ -1994,7 +1998,7 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
         struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
         struct link_config_limits limits;
         int common_len;
-        bool ret;
+        int ret;
 
         common_len = intel_dp_common_len_rate_limit(intel_dp,
                                                     intel_dp->max_link_rate);
@@ -2051,10 +2055,11 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
                                                         &limits);
 
         /* enable compression if the mode doesn't fit available BW */
-        if (!ret) {
-                if (!intel_dp_dsc_compute_config(intel_dp, pipe_config,
-                                                 conn_state, &limits))
-                        return false;
+        if (ret) {
+                ret = intel_dp_dsc_compute_config(intel_dp, pipe_config,
+                                                  conn_state, &limits);
+                if (ret < 0)
+                        return ret;
         }
 
         if (pipe_config->dsc_params.compression_enable) {
@@ -2079,10 +2084,10 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
                               intel_dp_max_data_rate(pipe_config->port_clock,
                                                      pipe_config->lane_count));
         }
-        return true;
+        return 0;
 }
 
-bool
+int
 intel_dp_compute_config(struct intel_encoder *encoder,
                         struct intel_crtc_state *pipe_config,
                         struct drm_connector_state *conn_state)
@@ -2098,6 +2103,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
                 to_intel_digital_connector_state(conn_state);
         bool constant_n = drm_dp_has_quirk(&intel_dp->desc,
                                            DP_DPCD_QUIRK_CONSTANT_N);
+        int ret;
 
         if (HAS_PCH_SPLIT(dev_priv) && !HAS_DDI(dev_priv) && port != PORT_A)
                 pipe_config->has_pch_encoder = true;
@@ -2119,8 +2125,6 @@ intel_dp_compute_config(struct intel_encoder *encoder,
                                        adjusted_mode);
 
                 if (INTEL_GEN(dev_priv) >= 9) {
-                        int ret;
-
                         ret = skl_update_scaler_crtc(pipe_config);
                         if (ret)
                                 return ret;
@@ -2135,20 +2139,21 @@ intel_dp_compute_config(struct intel_encoder *encoder,
         }
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         if (HAS_GMCH_DISPLAY(dev_priv) &&
             adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE)
-                return false;
+                return -EINVAL;
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK)
-                return false;
+                return -EINVAL;
 
         pipe_config->fec_enable = !intel_dp_is_edp(intel_dp) &&
                                   intel_dp_supports_fec(intel_dp, pipe_config);
 
-        if (!intel_dp_compute_link_config(encoder, pipe_config, conn_state))
-                return false;
+        ret = intel_dp_compute_link_config(encoder, pipe_config, conn_state);
+        if (ret < 0)
+                return ret;
 
         if (intel_conn_state->broadcast_rgb == INTEL_BROADCAST_RGB_AUTO) {
                 /*
@@ -2196,7 +2201,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 
         intel_psr_compute_config(intel_dp, pipe_config);
 
-        return true;
+        return 0;
 }
 
 void intel_dp_set_link_params(struct intel_dp *intel_dp,
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index c8e2215628e6..5899debe2184 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -30,9 +30,9 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_edid.h>
 
-static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
-                                        struct intel_crtc_state *pipe_config,
-                                        struct drm_connector_state *conn_state)
+static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
+                                       struct intel_crtc_state *pipe_config,
+                                       struct drm_connector_state *conn_state)
 {
         struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
         struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
@@ -53,7 +53,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
                                            DP_DPCD_QUIRK_CONSTANT_N);
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
         pipe_config->has_pch_encoder = false;
@@ -90,7 +90,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
                 if (slots < 0) {
                         DRM_DEBUG_KMS("failed finding vcpi slots:%d\n",
                                       slots);
-                        return false;
+                        return slots;
                 }
         }
 
@@ -108,7 +108,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 
         intel_ddi_compute_min_voltage_level(dev_priv, pipe_config);
 
-        return true;
+        return 0;
 }
 
 static int
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index a3252064b8d2..19d9abd2666e 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -222,9 +222,9 @@ struct intel_encoder {
         enum intel_output_type (*compute_output_type)(struct intel_encoder *,
                                                       struct intel_crtc_state *,
                                                       struct drm_connector_state *);
-        bool (*compute_config)(struct intel_encoder *,
-                               struct intel_crtc_state *,
-                               struct drm_connector_state *);
+        int (*compute_config)(struct intel_encoder *,
+                              struct intel_crtc_state *,
+                              struct drm_connector_state *);
         void (*pre_pll_enable)(struct intel_encoder *,
                                const struct intel_crtc_state *,
                                const struct drm_connector_state *);
@@ -1806,9 +1806,9 @@ void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
 void intel_dp_encoder_reset(struct drm_encoder *encoder);
 void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);
 void intel_dp_encoder_destroy(struct drm_encoder *encoder);
-bool intel_dp_compute_config(struct intel_encoder *encoder,
-                             struct intel_crtc_state *pipe_config,
-                             struct drm_connector_state *conn_state);
+int intel_dp_compute_config(struct intel_encoder *encoder,
+                            struct intel_crtc_state *pipe_config,
+                            struct drm_connector_state *conn_state);
 bool intel_dp_is_edp(struct intel_dp *intel_dp);
 bool intel_dp_is_port_edp(struct drm_i915_private *dev_priv, enum port port);
 enum irqreturn intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port,
@@ -1966,9 +1966,9 @@ void intel_hdmi_init(struct drm_i915_private *dev_priv, i915_reg_t hdmi_reg,
 void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
                                struct intel_connector *intel_connector);
 struct intel_hdmi *enc_to_intel_hdmi(struct drm_encoder *encoder);
-bool intel_hdmi_compute_config(struct intel_encoder *encoder,
-                               struct intel_crtc_state *pipe_config,
-                               struct drm_connector_state *conn_state);
+int intel_hdmi_compute_config(struct intel_encoder *encoder,
+                              struct intel_crtc_state *pipe_config,
+                              struct drm_connector_state *conn_state);
 bool intel_hdmi_handle_sink_scrambling(struct intel_encoder *encoder,
                                        struct drm_connector *connector,
                                        bool high_tmds_clock_ratio,
diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c
index 0042a7f69387..17a16917e134 100644
--- a/drivers/gpu/drm/i915/intel_dvo.c
+++ b/drivers/gpu/drm/i915/intel_dvo.c
@@ -235,9 +235,9 @@ intel_dvo_mode_valid(struct drm_connector *connector,
         return intel_dvo->dev.dev_ops->mode_valid(&intel_dvo->dev, mode);
 }
 
-static bool intel_dvo_compute_config(struct intel_encoder *encoder,
-                                     struct intel_crtc_state *pipe_config,
-                                     struct drm_connector_state *conn_state)
+static int intel_dvo_compute_config(struct intel_encoder *encoder,
+                                    struct intel_crtc_state *pipe_config,
+                                    struct drm_connector_state *conn_state)
 {
         struct intel_dvo *intel_dvo = enc_to_dvo(encoder);
         const struct drm_display_mode *fixed_mode =
@@ -254,10 +254,11 @@ static bool intel_dvo_compute_config(struct intel_encoder *encoder,
                 intel_fixed_panel_mode(fixed_mode, adjusted_mode);
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
-        return true;
+
+        return 0;
 }
 
 static void intel_dvo_pre_enable(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 55aeb97dd66d..1da7bb148fca 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1703,9 +1703,9 @@ intel_hdmi_ycbcr420_config(struct drm_connector *connector,
         return true;
 }
 
-bool intel_hdmi_compute_config(struct intel_encoder *encoder,
-                               struct intel_crtc_state *pipe_config,
-                               struct drm_connector_state *conn_state)
+int intel_hdmi_compute_config(struct intel_encoder *encoder,
+                              struct intel_crtc_state *pipe_config,
+                              struct drm_connector_state *conn_state)
 {
         struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&encoder->base);
         struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
@@ -1721,7 +1721,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
         bool force_dvi = intel_conn_state->force_audio == HDMI_AUDIO_OFF_DVI;
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
         pipe_config->has_hdmi_sink = !force_dvi && intel_hdmi->has_hdmi_sink;
@@ -1752,7 +1752,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
                                                 &clock_12bpc, &clock_10bpc,
                                                 &clock_8bpc)) {
                         DRM_ERROR("Can't support YCBCR420 output\n");
-                        return false;
+                        return -EINVAL;
                 }
         }
 
@@ -1802,7 +1802,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
         if (hdmi_port_clock_valid(intel_hdmi, pipe_config->port_clock,
                                   false, force_dvi) != MODE_OK) {
                 DRM_DEBUG_KMS("unsupported HDMI clock, rejecting mode\n");
-                return false;
+                return -EINVAL;
         }
 
         /* Set user selected PAR to incoming mode's member */
@@ -1821,7 +1821,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
                 }
         }
 
-        return true;
+        return 0;
 }
 
 static void
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index e6c5d985ea0a..3377d813dbb3 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -379,9 +379,9 @@ intel_lvds_mode_valid(struct drm_connector *connector,
         return MODE_OK;
 }
 
-static bool intel_lvds_compute_config(struct intel_encoder *intel_encoder,
-                                      struct intel_crtc_state *pipe_config,
-                                      struct drm_connector_state *conn_state)
+static int intel_lvds_compute_config(struct intel_encoder *intel_encoder,
+                                     struct intel_crtc_state *pipe_config,
+                                     struct drm_connector_state *conn_state)
 {
         struct drm_i915_private *dev_priv = to_i915(intel_encoder->base.dev);
         struct intel_lvds_encoder *lvds_encoder =
@@ -395,7 +395,7 @@ static bool intel_lvds_compute_config(struct intel_encoder *intel_encoder,
         /* Should never happen!! */
         if (INTEL_GEN(dev_priv) < 4 && intel_crtc->pipe == 0) {
                 DRM_ERROR("Can't support LVDS on pipe A\n");
-                return false;
+                return -EINVAL;
         }
 
         if (lvds_encoder->a3_power == LVDS_A3_POWER_UP)
@@ -421,7 +421,7 @@ static bool intel_lvds_compute_config(struct intel_encoder *intel_encoder,
                                adjusted_mode);
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         if (HAS_PCH_SPLIT(dev_priv)) {
                 pipe_config->has_pch_encoder = true;
@@ -440,7 +440,7 @@ static bool intel_lvds_compute_config(struct intel_encoder *intel_encoder,
          * user's requested refresh rate.
          */
 
-        return true;
+        return 0;
 }
 
 static enum drm_connector_status
diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 669fa9faad70..4a03b7f67dd5 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1108,9 +1108,9 @@ static void i9xx_adjust_sdvo_tv_clock(struct intel_crtc_state *pipe_config)
         pipe_config->clock_set = true;
 }
 
-static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
-                                      struct intel_crtc_state *pipe_config,
-                                      struct drm_connector_state *conn_state)
+static int intel_sdvo_compute_config(struct intel_encoder *encoder,
+                                     struct intel_crtc_state *pipe_config,
+                                     struct drm_connector_state *conn_state)
 {
         struct intel_sdvo *intel_sdvo = to_sdvo(encoder);
         struct intel_sdvo_connector_state *intel_sdvo_state =
@@ -1135,7 +1135,7 @@ static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
          */
         if (IS_TV(intel_sdvo_connector)) {
                 if (!intel_sdvo_set_output_timings_from_mode(intel_sdvo, mode))
-                        return false;
+                        return -EINVAL;
 
                 (void) intel_sdvo_get_preferred_input_mode(intel_sdvo,
                                                            intel_sdvo_connector,
@@ -1145,7 +1145,7 @@ static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
         } else if (IS_LVDS(intel_sdvo_connector)) {
                 if (!intel_sdvo_set_output_timings_from_mode(intel_sdvo,
                                                              intel_sdvo_connector->base.panel.fixed_mode))
-                        return false;
+                        return -EINVAL;
 
                 (void) intel_sdvo_get_preferred_input_mode(intel_sdvo,
                                                            intel_sdvo_connector,
@@ -1154,7 +1154,7 @@ static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
         }
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         /*
          * Make the CRTC code factor in the SDVO pixel multiplier.  The
@@ -1194,7 +1194,7 @@ static bool intel_sdvo_compute_config(struct intel_encoder *encoder,
         if (intel_sdvo_connector->is_hdmi)
                 adjusted_mode->picture_aspect_ratio = conn_state->picture_aspect_ratio;
 
-        return true;
+        return 0;
 }
 
 #define UPDATE_PROPERTY(input, NAME) \
diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
index 860f306a23ba..9bbe35a0f0f2 100644
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -870,7 +870,7 @@ intel_tv_get_config(struct intel_encoder *encoder,
         pipe_config->base.adjusted_mode.crtc_clock = pipe_config->port_clock;
 }
 
-static bool
+static int
 intel_tv_compute_config(struct intel_encoder *encoder,
                         struct intel_crtc_state *pipe_config,
                         struct drm_connector_state *conn_state)
@@ -880,10 +880,10 @@ intel_tv_compute_config(struct intel_encoder *encoder,
                 &pipe_config->base.adjusted_mode;
 
         if (!tv_mode)
-                return false;
+                return -EINVAL;
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
         adjusted_mode->crtc_clock = tv_mode->clock;
@@ -898,7 +898,7 @@ intel_tv_compute_config(struct intel_encoder *encoder,
          * or whether userspace is doing something stupid.
          */
 
-        return true;
+        return 0;
 }
 
 static void
diff --git a/drivers/gpu/drm/i915/vlv_dsi.c b/drivers/gpu/drm/i915/vlv_dsi.c
index 361e962a7969..9fc8085f76dc 100644
--- a/drivers/gpu/drm/i915/vlv_dsi.c
+++ b/drivers/gpu/drm/i915/vlv_dsi.c
@@ -257,9 +257,9 @@ static void band_gap_reset(struct drm_i915_private *dev_priv)
         mutex_unlock(&dev_priv->sb_lock);
 }
 
-static bool intel_dsi_compute_config(struct intel_encoder *encoder,
-                                     struct intel_crtc_state *pipe_config,
-                                     struct drm_connector_state *conn_state)
+static int intel_dsi_compute_config(struct intel_encoder *encoder,
+                                    struct intel_crtc_state *pipe_config,
+                                    struct drm_connector_state *conn_state)
 {
         struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
         struct intel_dsi *intel_dsi = container_of(encoder, struct intel_dsi,
@@ -285,7 +285,7 @@ static bool intel_dsi_compute_config(struct intel_encoder *encoder,
         }
 
         if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
-                return false;
+                return -EINVAL;
 
         /* DSI uses short packets for sync events, so clear mode flags for DSI */
         adjusted_mode->flags = 0;
@@ -303,16 +303,16 @@ static bool intel_dsi_compute_config(struct intel_encoder *encoder,
 
                 ret = bxt_dsi_pll_compute(encoder, pipe_config);
                 if (ret)
-                        return false;
+                        return -EINVAL;
         } else {
                 ret = vlv_dsi_pll_compute(encoder, pipe_config);
                 if (ret)
-                        return false;
+                        return -EINVAL;
         }
 
         pipe_config->clock_set = true;
 
-        return true;
+        return 0;
 }
 
 static bool glk_dsi_enable_io(struct intel_encoder *encoder)