diff options
| -rw-r--r-- | drivers/gpu/drm/i915/intel_sdvo.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c index 62d22ae4a1d1..e3b7a7ee39cb 100644 --- a/drivers/gpu/drm/i915/intel_sdvo.c +++ b/drivers/gpu/drm/i915/intel_sdvo.c @@ -1929,6 +1929,41 @@ static const struct drm_encoder_funcs intel_sdvo_enc_funcs = { .destroy = intel_sdvo_enc_destroy, }; +static void +intel_sdvo_guess_ddc_bus(struct intel_sdvo *sdvo) +{ + uint16_t mask = 0; + unsigned int num_bits; + + /* Make a mask of outputs less than or equal to our own priority in the + * list. + */ + switch (sdvo->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 &= sdvo->caps.output_flags; + num_bits = hweight16(mask); + /* If more than 3 outputs, default to DDC bus 3 for now. */ + if (num_bits > 3) + num_bits = 3; + + /* Corresponds to SDVO_CONTROL_BUS_DDCx */ + sdvo->ddc_bus = 1 << num_bits; +} /** * Choose the appropriate DDC bus for control bus switch command for this @@ -1948,7 +1983,10 @@ intel_sdvo_select_ddc_bus(struct drm_i915_private *dev_priv, else mapping = &(dev_priv->sdvo_mappings[1]); - sdvo->ddc_bus = 1 << ((mapping->ddc_pin & 0xf0) >> 4); + if (mapping->initialized) + sdvo->ddc_bus = 1 << ((mapping->ddc_pin & 0xf0) >> 4); + else + intel_sdvo_guess_ddc_bus(sdvo); } static bool |