drm/i915: Fix DDC bus selection for multifunction SDVO

Multifunction SDVO cards stopped working after 14571b4, and would report
something that looked remarkably like an ADD2 SPD ROM instead of EDID.
This appears to be because DDC bus selection was utterly horked by that
commit; controlled_output was no longer always a single bit, so
intel_sdvo_select_ddc_bus would pick bus 0, which is (unsurprisingly)
the SPD ROM bus, not a DDC bus.

So, instead of that, let's just use the DDC bus the child device table
tells us to use.  I'm guessing at the bitmask and shifting from VBIOS
dumps, but it can't possibly be worse.

cf. https://bugzilla.redhat.com/584229

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index bf11ad9998db705822f9f5212fd1ae876288330f..001e2f32be3fd67b78a39be6babe517f8237889c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -135,6 +135,7 @@ struct sdvo_device_mapping {
        u8 slave_addr;
        u8 dvo_wiring;
        u8 initialized;
+       u8 ddc_pin;
 };
 
 struct drm_i915_error_state {

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index f9ba452f0cbf2479649e7dbe947accdeed070f30..4c748d8f73d63a4da25f8ea10a981f7fc8860c2e 100644 (file)
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -366,6 +366,7 @@ parse_sdvo_device_mapping(struct drm_i915_private *dev_priv,
                        p_mapping->dvo_port = p_child->dvo_port;
                        p_mapping->slave_addr = p_child->slave_addr;
                        p_mapping->dvo_wiring = p_child->dvo_wiring;
+                       p_mapping->ddc_pin = p_child->ddc_pin;
                        p_mapping->initialized = 1;
                } else {
                        DRM_DEBUG_KMS("Maybe one SDVO port is shared by "

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 42ceb15da6898e16819960d48194669eeea6cff3..5192723637b5da09efbd4db0df7cc46364ed0722 100644 (file)
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -2054,40 +2054,17 @@ static const struct drm_encoder_funcs intel_sdvo_enc_funcs = {
  * outputs, then LVDS outputs.
  */
 static void
-intel_sdvo_select_ddc_bus(struct intel_sdvo_priv *dev_priv)
+intel_sdvo_select_ddc_bus(struct drm_i915_private *dev_priv,
+                         struct intel_sdvo_priv *sdvo, u32 reg)
 {
-       uint16_t mask = 0;
-       unsigned int num_bits;
+       struct sdvo_device_mapping *mapping;
 
-       /* Make a mask of outputs less than or equal to our own priority in the
-        * list.
-        */
-       switch (dev_priv->controlled_output) {
-       case SDVO_OUTPUT_LVDS1:
-               mask |= SDVO_OUTPUT_LVDS1;
-       case SDVO_OUTPUT_LVDS0:
-               mask |= SDVO_OUTPUT_LVDS0;
-       case SDVO_OUTPUT_TMDS1:
-               mask |= SDVO_OUTPUT_TMDS1;
-       case SDVO_OUTPUT_TMDS0:
-               mask |= SDVO_OUTPUT_TMDS0;
-       case SDVO_OUTPUT_RGB1:
-               mask |= SDVO_OUTPUT_RGB1;
-       case SDVO_OUTPUT_RGB0:
-               mask |= SDVO_OUTPUT_RGB0;
-               break;
-       }
-
-       /* Count bits to find what number we are in the priority list. */
-       mask &= dev_priv->caps.output_flags;
-       num_bits = hweight16(mask);
-       if (num_bits > 3) {
-               /* if more than 3 outputs, default to DDC bus 3 for now */
-               num_bits = 3;
-       }
+       if (IS_SDVOB(reg))
+               mapping = &(dev_priv->sdvo_mappings[0]);
+       else
+               mapping = &(dev_priv->sdvo_mappings[1]);
 
-       /* Corresponds to SDVO_CONTROL_BUS_DDCx */
-       dev_priv->ddc_bus = 1 << num_bits;
+       sdvo->ddc_bus = 1 << ((mapping->ddc_pin & 0xf0) >> 4);
 }
 
 static bool
@@ -2864,7 +2841,7 @@ bool intel_sdvo_init(struct drm_device *dev, int sdvo_reg)
                goto err_i2c;
        }
 
-       intel_sdvo_select_ddc_bus(sdvo_priv);
+       intel_sdvo_select_ddc_bus(dev_priv, sdvo_priv, sdvo_reg);
 
        /* Set the input timing to the screen. Assume always input 0. */
        intel_sdvo_set_target_input(intel_encoder, true, false);