[PATCH 09/10] drm/i915: disable DDI_BUF_CTL at the correct time

Paulo Zanoni
2012-10-05T15:06:35Z

And also properly wait for its idle bit.

You may notice that DDI_BUF_CTL is enabled in .enable but disabled in
.post_disable instead of .disable. Yes, the mode set sequence is not
exactly symmetrical, but let's assume the spec is correct unless we
can prove it's wrong.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
drivers/gpu/drm/i915/intel_ddi.c | 33 +++++++++++++++++++++++----------
1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index a4e05d0..5726acc 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1002,11 +1002,33 @@ void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
I915_WRITE(PORT_CLK_SEL(port), intel_crtc->ddi_pll_sel);
}

+static void intel_wait_ddi_buf_idle(struct drm_i915_private *dev_priv,
+ enum port port)
+{
+ uint32_t reg = DDI_BUF_CTL(port);
+ int i;
+
+ for (i = 0; i < 8; i++) {
+ udelay(1);
+ if (I915_READ(reg) & DDI_BUF_IS_IDLE)
+ return;
+ }
+ DRM_ERROR("Timeout waiting for DDI BUF %c idle bit\n", port_name(port));
+}
+
void intel_ddi_post_disable(struct intel_encoder *intel_encoder)
{
struct drm_encoder *encoder = &intel_encoder->base;
struct drm_i915_private *dev_priv = encoder->dev->dev_private;
enum port port = intel_ddi_get_encoder_port(intel_encoder);
+ uint32_t val;
+
+ val = I915_READ(DDI_BUF_CTL(port));
+ if (val & DDI_BUF_CTL_ENABLE) {
+ val &= ~DDI_BUF_CTL_ENABLE;
+ I915_WRITE(DDI_BUF_CTL(port), val);
+ intel_wait_ddi_buf_idle(dev_priv, port);
+ }

I915_WRITE(PORT_CLK_SEL(port), PORT_CLK_SEL_NONE);
}
@@ -1027,16 +1049,7 @@ void intel_enable_ddi(struct intel_encoder *encoder)

void intel_disable_ddi(struct intel_encoder *encoder)
{
- struct drm_device *dev = encoder->base.dev;
- struct drm_i915_private *dev_priv = dev->dev_private;
- struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&encoder->base);
- int port = intel_hdmi->ddi_port;
- u32 temp;
-
- temp = I915_READ(DDI_BUF_CTL(port));
- temp &= ~DDI_BUF_CTL_ENABLE;
-
- I915_WRITE(DDI_BUF_CTL(port), temp);
+ /* This will be needed in the future, so leave it here for now */
}

static int intel_ddi_get_cdclk_freq(struct drm_i915_private *dev_priv)
--
1.7.11.4