[V2] drm/i915/glk: Add Quirk for GLK NUC HDMI port issues.

Submitted by Clinton Taylor on June 13, 2018, 9:48 p.m.

Details

Message ID 1528926529-28676-1-git-send-email-clinton.a.taylor@intel.com
State New
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Series "drm/i915/glk: Add Quirk for GLK NUC HDMI port issues." ( rev: 2 ) in Intel GFX

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Commit Message

Clinton Taylor June 13, 2018, 9:48 p.m.
From: Clint Taylor <clinton.a.taylor@intel.com>

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.

V2: Add more devices to the quirk list

Cc: Imre Deak <imre.deak@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105887
Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h      |  1 +
 drivers/gpu/drm/i915/intel_ddi.c     |  8 ++++++++
 drivers/gpu/drm/i915/intel_display.c | 19 +++++++++++++++++++
 3 files changed, 28 insertions(+)

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index be8c2f0..da196b4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -656,6 +656,7 @@  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 ca73387..bc3d012 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1791,6 +1791,9 @@  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)
 {
@@ -1800,6 +1803,11 @@  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 8251e18..40e0306 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14749,6 +14749,17 @@  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;
@@ -14835,6 +14846,14 @@  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 },
+	{ 0x3184, 0x8086, 0x2072, quirk_increase_ddi_disabled_time },
+	/* ASRock ITX*/
+	{ 0x3185, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
+	{ 0x3184, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
+
 };
 
 static void intel_init_quirks(struct drm_device *dev)

Comments

Am Wed, 13 Jun 2018 14:48:49 -0700
schrieb clinton.a.taylor@intel.com:

> From: Clint Taylor <clinton.a.taylor@intel.com>
> 
> 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.
> 
> V2: Add more devices to the quirk list
> 
> Cc: Imre Deak <imre.deak@intel.com>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105887
> Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>

Tested-by: Daniel Scheller <d.scheller.oss@gmail.com>

on an ASRock J5005-ITX with a 0x3184 GLK GPU for the last five days,
HDMI signal issues when the pixel clock goes up are gone.

> ---
>  drivers/gpu/drm/i915/i915_drv.h      |  1 +
>  drivers/gpu/drm/i915/intel_ddi.c     |  8 ++++++++
>  drivers/gpu/drm/i915/intel_display.c | 19 +++++++++++++++++++
>  3 files changed, 28 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index be8c2f0..da196b4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -656,6 +656,7 @@ 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 ca73387..bc3d012 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1791,6 +1791,9 @@ 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)
>  {
> @@ -1800,6 +1803,11 @@ 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 8251e18..40e0306 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -14749,6 +14749,17 @@ 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;
> @@ -14835,6 +14846,14 @@ 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 },
> +	{ 0x3184, 0x8086, 0x2072, quirk_increase_ddi_disabled_time },
> +	/* ASRock ITX*/
> +	{ 0x3185, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
> +	{ 0x3184, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
> +
>  };
>  
>  static void intel_init_quirks(struct drm_device *dev)

Best regards,
Daniel Scheller
On Wed, Jun 13, 2018 at 02:48:49PM -0700, clinton.a.taylor@intel.com wrote:
> From: Clint Taylor <clinton.a.taylor@intel.com>
> 
> 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.
> 
> V2: Add more devices to the quirk list
> 
> Cc: Imre Deak <imre.deak@intel.com>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105887
> Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h      |  1 +
>  drivers/gpu/drm/i915/intel_ddi.c     |  8 ++++++++
>  drivers/gpu/drm/i915/intel_display.c | 19 +++++++++++++++++++
>  3 files changed, 28 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index be8c2f0..da196b4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -656,6 +656,7 @@ 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 ca73387..bc3d012 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1791,6 +1791,9 @@ 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)
>  {
> @@ -1800,6 +1803,11 @@ 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");

No need for the define or the debug message here imo. msleep() can be
inaccurate (even sleeping less than expected), so I'd use a bigger
margin, sleeping say 100ms.

If the problem is with the HDMI retimer chip, we should limit the quirk
to HDMI outputs. 

> +	}
>  }
>  
>  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 8251e18..40e0306 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -14749,6 +14749,17 @@ 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;
> @@ -14835,6 +14846,14 @@ 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 },
> +	{ 0x3184, 0x8086, 0x2072, quirk_increase_ddi_disabled_time },
> +	/* ASRock ITX*/
> +	{ 0x3185, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
> +	{ 0x3184, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
> +

Extra w/s. A quirk list looks ok for now since we can't identify the
retimer chip in any other way.

>  };
>  
>  static void intel_init_quirks(struct drm_device *dev)
> -- 
> 1.9.1
>
On 06/25/2018 03:33 AM, Imre Deak wrote:
> On Wed, Jun 13, 2018 at 02:48:49PM -0700, clinton.a.taylor@intel.com wrote:
>> From: Clint Taylor <clinton.a.taylor@intel.com>
>>
>> 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.
>>
>> V2: Add more devices to the quirk list
>>
>> Cc: Imre Deak <imre.deak@intel.com>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105887
>> Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_drv.h      |  1 +
>>   drivers/gpu/drm/i915/intel_ddi.c     |  8 ++++++++
>>   drivers/gpu/drm/i915/intel_display.c | 19 +++++++++++++++++++
>>   3 files changed, 28 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index be8c2f0..da196b4 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -656,6 +656,7 @@ 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 ca73387..bc3d012 100644
>> --- a/drivers/gpu/drm/i915/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>> @@ -1791,6 +1791,9 @@ 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)
>>   {
>> @@ -1800,6 +1803,11 @@ 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");
> No need for the define or the debug message here imo. msleep() can be
> inaccurate (even sleeping less than expected), so I'd use a bigger
> margin, sleeping say 100ms.

Easy to do and I can submit v3.

>
> If the problem is with the HDMI retimer chip, we should limit the quirk
> to HDMI outputs.
Output type is not available in intel_disable_ddi() and I would prefer 
not to change the interface only for the quirk. I could move the quirk 
execution up a level to haswell_crtc_disable() and detect the 
old_crtc_state->type before executing the quirk. However, the quirk is 
only being detected for certain boards that only have HDMI outputs. 
Unless more boards are added to the quirk_list[] we really don't need 
logic to detect HDMI outputs.

-Clint

>> +	}
>>   }
>>   
>>   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 8251e18..40e0306 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -14749,6 +14749,17 @@ 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;
>> @@ -14835,6 +14846,14 @@ 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 },
>> +	{ 0x3184, 0x8086, 0x2072, quirk_increase_ddi_disabled_time },
>> +	/* ASRock ITX*/
>> +	{ 0x3185, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
>> +	{ 0x3184, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
>> +
> Extra w/s. A quirk list looks ok for now since we can't identify the
> retimer chip in any other way.
>
>>   };
>>   
>>   static void intel_init_quirks(struct drm_device *dev)
>> -- 
>> 1.9.1
>>
On Wed, Jun 27, 2018 at 03:26:54PM -0700, Clint Taylor wrote:
> 
> 
> On 06/25/2018 03:33 AM, Imre Deak wrote:
> > On Wed, Jun 13, 2018 at 02:48:49PM -0700, clinton.a.taylor@intel.com wrote:
> > > From: Clint Taylor <clinton.a.taylor@intel.com>
> > > 
> > > 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.
> > > 
> > > V2: Add more devices to the quirk list
> > > 
> > > Cc: Imre Deak <imre.deak@intel.com>
> > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105887
> > > Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
> > > ---
> > >   drivers/gpu/drm/i915/i915_drv.h      |  1 +
> > >   drivers/gpu/drm/i915/intel_ddi.c     |  8 ++++++++
> > >   drivers/gpu/drm/i915/intel_display.c | 19 +++++++++++++++++++
> > >   3 files changed, 28 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > > index be8c2f0..da196b4 100644
> > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > @@ -656,6 +656,7 @@ 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 ca73387..bc3d012 100644
> > > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > > @@ -1791,6 +1791,9 @@ 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)
> > >   {
> > > @@ -1800,6 +1803,11 @@ 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");
> > No need for the define or the debug message here imo. msleep() can be
> > inaccurate (even sleeping less than expected), so I'd use a bigger
> > margin, sleeping say 100ms.
> 
> Easy to do and I can submit v3.
> 
> > 
> > If the problem is with the HDMI retimer chip, we should limit the quirk
> > to HDMI outputs.
> Output type is not available in intel_disable_ddi() and I would prefer not
> to change the interface only for the quirk. I could move the quirk execution
> up a level to haswell_crtc_disable() and detect the old_crtc_state->type
> before executing the quirk. However, the quirk is only being detected for
> certain boards that only have HDMI outputs. Unless more boards are added to
> the quirk_list[] we really don't need logic to detect HDMI outputs.

Ok, but I'm sure we'll forget about this detail once we have to update
the list with a GLK having a DP output too. OTOH, changing
intel_ddi_disable_transcoder_func() to accept
struct intel_crtc_state *crtc_state would make it symmetric with
intel_ddi_enable_transcoder_func(), so imo a good change on its own.

--Imre

> 
> -Clint
> 
> > > +	}
> > >   }
> > >   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 8251e18..40e0306 100644
> > > --- a/drivers/gpu/drm/i915/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/intel_display.c
> > > @@ -14749,6 +14749,17 @@ 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;
> > > @@ -14835,6 +14846,14 @@ 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 },
> > > +	{ 0x3184, 0x8086, 0x2072, quirk_increase_ddi_disabled_time },
> > > +	/* ASRock ITX*/
> > > +	{ 0x3185, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
> > > +	{ 0x3184, 0x1849, 0x2212, quirk_increase_ddi_disabled_time },
> > > +
> > Extra w/s. A quirk list looks ok for now since we can't identify the
> > retimer chip in any other way.
> > 
> > >   };
> > >   static void intel_init_quirks(struct drm_device *dev)
> > > -- 
> > > 1.9.1
> > > 
>