drm/i915: disable DIP while changing the port

The register specification says we need to do this.

V2: Only write the register if the port is enabled.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 620b0dba9e7a87c810a961a556a5fe9dca4029c6..c858da986fdd2f5a4da9f10dd9806de29996c3ba 100644 (file)
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -317,6 +317,7 @@ static void g4x_set_infoframes(struct drm_encoder *encoder,
        struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);
        u32 reg = VIDEO_DIP_CTL;
        u32 val = I915_READ(reg);
+       u32 port;
 
        /* If the registers were not initialized yet, they might be zeroes,
         * which means we're selecting the AVI DIP and we're setting its
@@ -337,18 +338,26 @@ static void g4x_set_infoframes(struct drm_encoder *encoder,
                return;
        }
 
-       val &= ~VIDEO_DIP_PORT_MASK;
        switch (intel_hdmi->sdvox_reg) {
        case SDVOB:
-               val |= VIDEO_DIP_PORT_B;
+               port = VIDEO_DIP_PORT_B;
                break;
        case SDVOC:
-               val |= VIDEO_DIP_PORT_C;
+               port = VIDEO_DIP_PORT_C;
                break;
        default:
                return;
        }
 
+       if (port != (val & VIDEO_DIP_PORT_MASK)) {
+               if (val & VIDEO_DIP_ENABLE) {
+                       val &= ~VIDEO_DIP_ENABLE;
+                       I915_WRITE(reg, val);
+               }
+               val &= ~VIDEO_DIP_PORT_MASK;
+               val |= port;
+       }
+
        val |= VIDEO_DIP_ENABLE;
        val &= ~VIDEO_DIP_ENABLE_VENDOR;
 
@@ -366,6 +375,7 @@ static void ibx_set_infoframes(struct drm_encoder *encoder,
        struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder);
        u32 reg = TVIDEO_DIP_CTL(intel_crtc->pipe);
        u32 val = I915_READ(reg);
+       u32 port;
 
        /* See the big comment in g4x_set_infoframes() */
        val |= VIDEO_DIP_SELECT_AVI | VIDEO_DIP_FREQ_VSYNC;
@@ -378,21 +388,29 @@ static void ibx_set_infoframes(struct drm_encoder *encoder,
                return;
        }
 
-       val &= ~VIDEO_DIP_PORT_MASK;
        switch (intel_hdmi->sdvox_reg) {
        case HDMIB:
-               val |= VIDEO_DIP_PORT_B;
+               port = VIDEO_DIP_PORT_B;
                break;
        case HDMIC:
-               val |= VIDEO_DIP_PORT_C;
+               port = VIDEO_DIP_PORT_C;
                break;
        case HDMID:
-               val |= VIDEO_DIP_PORT_D;
+               port = VIDEO_DIP_PORT_D;
                break;
        default:
                return;
        }
 
+       if (port != (val & VIDEO_DIP_PORT_MASK)) {
+               if (val & VIDEO_DIP_ENABLE) {
+                       val &= ~VIDEO_DIP_ENABLE;
+                       I915_WRITE(reg, val);
+               }
+               val &= ~VIDEO_DIP_PORT_MASK;
+               val |= port;
+       }
+
        val |= VIDEO_DIP_ENABLE;
        val &= ~(VIDEO_DIP_ENABLE_VENDOR | VIDEO_DIP_ENABLE_GAMUT |
                 VIDEO_DIP_ENABLE_GCP);