From: Clint Taylor <clinton.a.taylor@xxxxxxxxx> On GLK NUC platforms the HDMI retiming buffer needs additional disabled time to correctly sync to a faster incoming signal. When measured on a scope the highspeed lines of the HDMI clock turn off for ~400uS during a normal resolution change. The HDMI retimer on the GLK NUC appears to require at least a full frame of quiet time before a new faster clock can be correctly sync'd. The worst case scenario appears to be 23.98Hz modes which requires a wait of 41.25ms. Add a quirk to the driver for GLK NUC that waits 42ms. Cc: Imre Deak <imre.deak@xxxxxxxxx> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105887 Signed-off-by: Clint Taylor <clinton.a.taylor@xxxxxxxxx> --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_ddi.c | 8 ++++++++ drivers/gpu/drm/i915/intel_display.c | 14 ++++++++++++++ 3 files changed, 23 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index c407366..628491d 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -645,6 +645,7 @@ enum intel_sbi_destination { #define QUIRK_BACKLIGHT_PRESENT (1<<3) #define QUIRK_PIN_SWIZZLED_PAGES (1<<5) #define QUIRK_INCREASE_T12_DELAY (1<<6) +#define QUIRK_INCREASE_DDI_DISABLED_TIME (1<<7) struct intel_fbdev; struct intel_fbc_work; diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index b344e0f..61b41c3 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -1784,6 +1784,9 @@ void intel_ddi_enable_transcoder_func(const struct intel_crtc_state *crtc_state) I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), temp); } +/* Quirk time computed based on 24fps frame time of 41.25ms */ +#define DDI_DISABLED_QUIRK_TIME 42 + void intel_ddi_disable_transcoder_func(struct drm_i915_private *dev_priv, enum transcoder cpu_transcoder) { @@ -1793,6 +1796,11 @@ void intel_ddi_disable_transcoder_func(struct drm_i915_private *dev_priv, val &= ~(TRANS_DDI_FUNC_ENABLE | TRANS_DDI_PORT_MASK | TRANS_DDI_DP_VC_PAYLOAD_ALLOC); val |= TRANS_DDI_PORT_NONE; I915_WRITE(reg, val); + + if (dev_priv->quirks & QUIRK_INCREASE_DDI_DISABLED_TIME) { + msleep(DDI_DISABLED_QUIRK_TIME); + DRM_DEBUG_KMS("Quirk Increase DDI disabled time\n"); + } } int intel_ddi_toggle_hdcp_signalling(struct intel_encoder *intel_encoder, diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index ed29219..0d07c37 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -14740,6 +14740,17 @@ static void quirk_increase_t12_delay(struct drm_device *dev) DRM_INFO("Applying T12 delay quirk\n"); } +/* GeminiLake NUC HDMI outputs require additional off time + * this allows the onboard retimer to correctly sync to signal + */ +static void quirk_increase_ddi_disabled_time(struct drm_device *dev) +{ + struct drm_i915_private *dev_priv = to_i915(dev); + + dev_priv->quirks |= QUIRK_INCREASE_DDI_DISABLED_TIME; + DRM_INFO("Applying Increase DDI Disabled quirk\n"); +} + struct intel_quirk { int device; int subsystem_vendor; @@ -14826,6 +14837,9 @@ static int intel_dmi_reverse_brightness(const struct dmi_system_id *id) /* Toshiba Satellite P50-C-18C */ { 0x191B, 0x1179, 0xF840, quirk_increase_t12_delay }, + + /* GeminiLake NUC */ + { 0x3185, 0x8086, 0x2072, quirk_increase_ddi_disabled_time }, }; static void intel_init_quirks(struct drm_device *dev) -- 1.9.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
