[PATCH v4 0/2] drm/i915/display: Limit scaler count and disable pipe joiner on WCL

[PATCH v4 0/2] drm/i915/display: Limit scaler count and disable pipe joiner on WCL

[Vidya Srinivas]

Pipe joining is not supported in the WCL display configuration.
Modes that would require joining are rejected, matching the
4k 60Hz maximum resolution documented for the platform.

Also, WCL supports a single pipe scaler instead of two.

Vidya Srinivas (2):
  drm/i915/display: Single scaler per pipe on WCL
  drm/i915/display: Disable pipe joiner on WCL

 drivers/gpu/drm/i915/display/intel_display_device.c | 5 ++++-
 drivers/gpu/drm/i915/display/intel_dp.c             | 4 ++--
 2 files changed, 6 insertions(+), 3 deletions(-)

-- 
2.45.2

[PATCH v4 1/2] drm/i915/display: Single scaler per pipe on WCL

[Vidya Srinivas]

WCL has only one scaler per pipe. Set num_scalers to 1 for
WCL.

v2: Rebase onto latest upstream
v3: Fix up the commit message
v4: Split the scaler and joiner changes into separate patches (Jani)

Bspec: 74286
Cc: stable@vger.kernel.org
Suggested-by: Charlton Lin <charlton.lin@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display_device.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
index f17fc2c68472..c74256359c25 100644
--- a/drivers/gpu/drm/i915/display/intel_display_device.c
+++ b/drivers/gpu/drm/i915/display/intel_display_device.c
@@ -1813,7 +1813,10 @@ static void __intel_display_device_info_runtime_init(struct intel_display *displ
 	if (intel_display_wa(display, INTEL_DISPLAY_WA_14011765242))
 		for_each_pipe(display, pipe)
 			display_runtime->num_scalers[pipe] = 0;
-	else if (DISPLAY_VER(display) >= 11) {
+	else if (DISPLAY_VERx100(display) == 3002) {
+		for_each_pipe(display, pipe)
+			display_runtime->num_scalers[pipe] = 1;
+	} else if (DISPLAY_VER(display) >= 11) {
 		for_each_pipe(display, pipe)
 			display_runtime->num_scalers[pipe] = 2;
 	} else if (DISPLAY_VER(display) >= 9) {
-- 
2.45.2

RE: [PATCH v4 1/2] drm/i915/display: Single scaler per pipe on WCL

[Srinivas, Vidya]

> -----Original Message-----
> From: Srinivas, Vidya <vidya.srinivas@intel.com>
> Sent: 28 October 2026 12:34
> To: intel-gfx@lists.freedesktop.org
> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Srinivas, Vidya
> <vidya.srinivas@intel.com>; Lin, Charlton <charlton.lin@intel.com>
> Subject: [PATCH v4 1/2] drm/i915/display: Single scaler per pipe on WCL
> 
> WCL has only one scaler per pipe. Set num_scalers to 1 for WCL.
> 
> v2: Rebase onto latest upstream
> v3: Fix up the commit message
> v4: Split the scaler and joiner changes into separate patches (Jani)

Adding fixes tag:
Fixes: 632633d095b6 ("drm/i915/wcl: Add display device info")

> 
> Bspec: 74286
> Cc: stable@vger.kernel.org
> Suggested-by: Charlton Lin <charlton.lin@intel.com>
> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_device.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c
> b/drivers/gpu/drm/i915/display/intel_display_device.c
> index f17fc2c68472..c74256359c25 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -1813,7 +1813,10 @@ static void
> __intel_display_device_info_runtime_init(struct intel_display *displ
>  	if (intel_display_wa(display, INTEL_DISPLAY_WA_14011765242))
>  		for_each_pipe(display, pipe)
>  			display_runtime->num_scalers[pipe] = 0;
> -	else if (DISPLAY_VER(display) >= 11) {
> +	else if (DISPLAY_VERx100(display) == 3002) {
> +		for_each_pipe(display, pipe)
> +			display_runtime->num_scalers[pipe] = 1;
> +	} else if (DISPLAY_VER(display) >= 11) {
>  		for_each_pipe(display, pipe)
>  			display_runtime->num_scalers[pipe] = 2;
>  	} else if (DISPLAY_VER(display) >= 9) {
> --
> 2.45.2

RE: [PATCH v4 1/2] drm/i915/display: Single scaler per pipe on WCL

[Srinivas, Vidya]

> -----Original Message-----
> From: Srinivas, Vidya
> Sent: 28 October 2026 21:28
> To: intel-gfx@lists.freedesktop.org
> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Lin, Charlton
> <Charlton.Lin@intel.com>
> Subject: RE: [PATCH v4 1/2] drm/i915/display: Single scaler per pipe on WCL
> 
> 
> 
> > -----Original Message-----
> > From: Srinivas, Vidya <vidya.srinivas@intel.com>
> > Sent: 28 October 2026 12:34
> > To: intel-gfx@lists.freedesktop.org
> > Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar,
> > Uma <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Srinivas,
> > Vidya <vidya.srinivas@intel.com>; Lin, Charlton
> > <charlton.lin@intel.com>
> > Subject: [PATCH v4 1/2] drm/i915/display: Single scaler per pipe on
> > WCL
> >
> > WCL has only one scaler per pipe. Set num_scalers to 1 for WCL.
> >
> > v2: Rebase onto latest upstream
> > v3: Fix up the commit message
> > v4: Split the scaler and joiner changes into separate patches (Jani)
> 
> Adding fixes tag:
> Fixes: 632633d095b6 ("drm/i915/wcl: Add display device info")
> 

  Sorry, since pipe auto-discovery via DFSM was already
  effective when 30.02 was enabled, the joiner was wrongly allowed from
  f8e1c3e07db1 onwards. Updating fixes tag:
 
  Fixes: f8e1c3e07db1 ("drm/i915/xe3lpd: Add support for display version 30.02")

> >
> > Bspec: 74286
> > Cc: stable@vger.kernel.org
> > Suggested-by: Charlton Lin <charlton.lin@intel.com>
> > Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> > Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_display_device.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c
> > b/drivers/gpu/drm/i915/display/intel_display_device.c
> > index f17fc2c68472..c74256359c25 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> > @@ -1813,7 +1813,10 @@ static void
> > __intel_display_device_info_runtime_init(struct intel_display *displ
> >  	if (intel_display_wa(display, INTEL_DISPLAY_WA_14011765242))
> >  		for_each_pipe(display, pipe)
> >  			display_runtime->num_scalers[pipe] = 0;
> > -	else if (DISPLAY_VER(display) >= 11) {
> > +	else if (DISPLAY_VERx100(display) == 3002) {
> > +		for_each_pipe(display, pipe)
> > +			display_runtime->num_scalers[pipe] = 1;
> > +	} else if (DISPLAY_VER(display) >= 11) {
> >  		for_each_pipe(display, pipe)
> >  			display_runtime->num_scalers[pipe] = 2;
> >  	} else if (DISPLAY_VER(display) >= 9) {
> > --
> > 2.45.2

[PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL

[Vidya Srinivas]

Pipe joining is not supported in the WCL display configuration.
Report no joiner support on WCL so that modes which would require
joining are rejected, matching the 4k 60Hz maximum resolution
documented for the platform.

v2: Rebase onto latest upstream
v3: Fix up the commit message
v4: Split the scaler and joiner changes into separate patches (Jani)

Bspec: 74286
Cc: stable@vger.kernel.org
Suggested-by: Charlton Lin <charlton.lin@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 00e02e019d25..ef164a797618 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
 			return false;
 	}
 
-	return DISPLAY_VER(display) >= 12 ||
+	return ((DISPLAY_VER(display) >= 12 && DISPLAY_VERx100(display) != 3002) ||
 		(DISPLAY_VER(display) == 11 &&
-		 encoder->port != PORT_A);
+		 encoder->port != PORT_A));
 }
 
 static int dg2_max_source_rate(struct intel_dp *intel_dp)
-- 
2.45.2

Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL

[Borah, Chaitanya Kumar]

On 10/28/2026 12:34 PM, Vidya Srinivas wrote:
> Pipe joining is not supported in the WCL display configuration.
> Report no joiner support on WCL so that modes which would require
> joining are rejected, matching the 4k 60Hz maximum resolution
> documented for the platform.
> 
> v2: Rebase onto latest upstream
> v3: Fix up the commit message
> v4: Split the scaler and joiner changes into separate patches (Jani)
> 
> Bspec: 74286
> Cc: stable@vger.kernel.org

Won't we need a Fixes tag to tell where this change need to go to?

> Suggested-by: Charlton Lin <charlton.lin@intel.com>
> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 00e02e019d25..ef164a797618 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
>   			return false;
>   	}
>   
> -	return DISPLAY_VER(display) >= 12 ||
> +	return ((DISPLAY_VER(display) >= 12 && DISPLAY_VERx100(display) != 3002) ||
>   		(DISPLAY_VER(display) == 11 &&
> -		 encoder->port != PORT_A);
> +		 encoder->port != PORT_A));
>   }
>   
>   static int dg2_max_source_rate(struct intel_dp *intel_dp)

RE: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL

[Srinivas, Vidya]

> -----Original Message-----
> From: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
> Sent: 28 October 2026 14:08
> To: Srinivas, Vidya <vidya.srinivas@intel.com>; intel-gfx@lists.freedesktop.org
> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Lin, Charlton
> <charlton.lin@intel.com>
> Subject: Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL
> 
> 
> 
> On 10/28/2026 12:34 PM, Vidya Srinivas wrote:
> > Pipe joining is not supported in the WCL display configuration.
> > Report no joiner support on WCL so that modes which would require
> > joining are rejected, matching the 4k 60Hz maximum resolution
> > documented for the platform.
> >
> > v2: Rebase onto latest upstream
> > v3: Fix up the commit message
> > v4: Split the scaler and joiner changes into separate patches (Jani)
> >
> > Bspec: 74286
> > Cc: stable@vger.kernel.org
> 
> Won't we need a Fixes tag to tell where this change need to go to?

Hello Chaitanya,

Thank you. Yes, I did check checkpatch gave the same warning but I couldn’t find the exact patch to call out the fixes
There are patches like Extend the max dotclock limit to WCL, Restrict max source rate for WCL to HBR3,
drm/i915/wcl: Add display device info, Add power well mapping for WCL etc.
git log shows under merge tag the "Add support for Wildcat Lake (WCL) display, version 30.02"
So, could not find the patch for which I could mention fixes.

Regards
Vidya

> 
> > Suggested-by: Charlton Lin <charlton.lin@intel.com>
> > Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> > Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> > ---
> >   drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 00e02e019d25..ef164a797618 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
> >   			return false;
> >   	}
> >
> > -	return DISPLAY_VER(display) >= 12 ||
> > +	return ((DISPLAY_VER(display) >= 12 && DISPLAY_VERx100(display) !=
> > +3002) ||
> >   		(DISPLAY_VER(display) == 11 &&
> > -		 encoder->port != PORT_A);
> > +		 encoder->port != PORT_A));
> >   }
> >
> >   static int dg2_max_source_rate(struct intel_dp *intel_dp)

Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL

[Borah, Chaitanya Kumar]

On 10/28/2026 2:27 PM, Srinivas, Vidya wrote:
> 
> 
>> -----Original Message-----
>> From: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
>> Sent: 28 October 2026 14:08
>> To: Srinivas, Vidya <vidya.srinivas@intel.com>; intel-gfx@lists.freedesktop.org
>> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
>> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Lin, Charlton
>> <charlton.lin@intel.com>
>> Subject: Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL
>>
>>
>>
>> On 10/28/2026 12:34 PM, Vidya Srinivas wrote:
>>> Pipe joining is not supported in the WCL display configuration.
>>> Report no joiner support on WCL so that modes which would require
>>> joining are rejected, matching the 4k 60Hz maximum resolution
>>> documented for the platform.
>>>
>>> v2: Rebase onto latest upstream
>>> v3: Fix up the commit message
>>> v4: Split the scaler and joiner changes into separate patches (Jani)
>>>
>>> Bspec: 74286
>>> Cc: stable@vger.kernel.org
>>
>> Won't we need a Fixes tag to tell where this change need to go to?
> 
> Hello Chaitanya,
> 
> Thank you. Yes, I did check checkpatch gave the same warning but I couldn’t find the exact patch to call out the fixes
> There are patches like Extend the max dotclock limit to WCL, Restrict max source rate for WCL to HBR3,
> drm/i915/wcl: Add display device info, Add power well mapping for WCL etc.
> git log shows under merge tag the "Add support for Wildcat Lake (WCL) display, version 30.02"
> So, could not find the patch for which I could mention fixes.

Fixes: 632633d095b6 ("drm/i915/wcl: Add display device info")

Should be sufficient.

> 
> Regards
> Vidya
> 
>>
>>> Suggested-by: Charlton Lin <charlton.lin@intel.com>
>>> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
>>> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
>>> ---
>>>    drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>>> b/drivers/gpu/drm/i915/display/intel_dp.c
>>> index 00e02e019d25..ef164a797618 100644
>>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>>> @@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
>>>    			return false;
>>>    	}
>>>
>>> -	return DISPLAY_VER(display) >= 12 ||
>>> +	return ((DISPLAY_VER(display) >= 12 && DISPLAY_VERx100(display) !=
>>> +3002) ||
>>>    		(DISPLAY_VER(display) == 11 &&
>>> -		 encoder->port != PORT_A);
>>> +		 encoder->port != PORT_A));
>>>    }
>>>
>>>    static int dg2_max_source_rate(struct intel_dp *intel_dp)
> 

Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL

[Borah, Chaitanya Kumar]

On 10/28/2026 2:58 PM, Borah, Chaitanya Kumar wrote:
> 
> 
> On 10/28/2026 2:27 PM, Srinivas, Vidya wrote:
>>
>>
>>> -----Original Message-----
>>> From: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
>>> Sent: 28 October 2026 14:08
>>> To: Srinivas, Vidya <vidya.srinivas@intel.com>; intel- 
>>> gfx@lists.freedesktop.org
>>> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
>>> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Lin, Charlton
>>> <charlton.lin@intel.com>
>>> Subject: Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL
>>>
>>>
>>>
>>> On 10/28/2026 12:34 PM, Vidya Srinivas wrote:
>>>> Pipe joining is not supported in the WCL display configuration.
>>>> Report no joiner support on WCL so that modes which would require
>>>> joining are rejected, matching the 4k 60Hz maximum resolution
>>>> documented for the platform.
>>>>
>>>> v2: Rebase onto latest upstream
>>>> v3: Fix up the commit message
>>>> v4: Split the scaler and joiner changes into separate patches (Jani)
>>>>
>>>> Bspec: 74286
>>>> Cc: stable@vger.kernel.org
>>>
>>> Won't we need a Fixes tag to tell where this change need to go to?
>>
>> Hello Chaitanya,
>>
>> Thank you. Yes, I did check checkpatch gave the same warning but I 
>> couldn’t find the exact patch to call out the fixes
>> There are patches like Extend the max dotclock limit to WCL, Restrict 
>> max source rate for WCL to HBR3,
>> drm/i915/wcl: Add display device info, Add power well mapping for WCL 
>> etc.
>> git log shows under merge tag the "Add support for Wildcat Lake (WCL) 
>> display, version 30.02"
>> So, could not find the patch for which I could mention fixes.
> 
> Fixes: 632633d095b6 ("drm/i915/wcl: Add display device info")
> 
> Should be sufficient.
> 

Sorry, support for the device id was added even before that.

Better fit.

Fixes: f8e1c3e07db1 ("drm/i915/xe3lpd: Add support for display version 
30.02")

It would be worth checking though if these patches applies as is or 
might need some rebase.

==
Chaitanya

>>
>> Regards
>> Vidya
>>
>>>
>>>> Suggested-by: Charlton Lin <charlton.lin@intel.com>
>>>> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
>>>> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
>>>> ---
>>>>    drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
>>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>>>> b/drivers/gpu/drm/i915/display/intel_dp.c
>>>> index 00e02e019d25..ef164a797618 100644
>>>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>>>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>>>> @@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
>>>>                return false;
>>>>        }
>>>>
>>>> -    return DISPLAY_VER(display) >= 12 ||
>>>> +    return ((DISPLAY_VER(display) >= 12 && DISPLAY_VERx100(display) !=
>>>> +3002) ||
>>>>            (DISPLAY_VER(display) == 11 &&
>>>> -         encoder->port != PORT_A);
>>>> +         encoder->port != PORT_A));
>>>>    }
>>>>
>>>>    static int dg2_max_source_rate(struct intel_dp *intel_dp)
>>
> 

RE: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL

[Srinivas, Vidya]

> -----Original Message-----
> From: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
> Sent: 28 October 2026 15:07
> To: Srinivas, Vidya <vidya.srinivas@intel.com>; intel-gfx@lists.freedesktop.org
> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Lin, Charlton
> <charlton.lin@intel.com>
> Subject: Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL
> 
> 
> 
> On 10/28/2026 2:58 PM, Borah, Chaitanya Kumar wrote:
> >
> >
> > On 10/28/2026 2:27 PM, Srinivas, Vidya wrote:
> >>
> >>
> >>> -----Original Message-----
> >>> From: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
> >>> Sent: 28 October 2026 14:08
> >>> To: Srinivas, Vidya <vidya.srinivas@intel.com>; intel-
> >>> gfx@lists.freedesktop.org
> >>> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar,
> >>> Uma <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Lin,
> >>> Charlton <charlton.lin@intel.com>
> >>> Subject: Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on
> >>> WCL
> >>>
> >>>
> >>>
> >>> On 10/28/2026 12:34 PM, Vidya Srinivas wrote:
> >>>> Pipe joining is not supported in the WCL display configuration.
> >>>> Report no joiner support on WCL so that modes which would require
> >>>> joining are rejected, matching the 4k 60Hz maximum resolution
> >>>> documented for the platform.
> >>>>
> >>>> v2: Rebase onto latest upstream
> >>>> v3: Fix up the commit message
> >>>> v4: Split the scaler and joiner changes into separate patches
> >>>> (Jani)
> >>>>
> >>>> Bspec: 74286
> >>>> Cc: stable@vger.kernel.org
> >>>
> >>> Won't we need a Fixes tag to tell where this change need to go to?
> >>
> >> Hello Chaitanya,
> >>
> >> Thank you. Yes, I did check checkpatch gave the same warning but I
> >> couldn’t find the exact patch to call out the fixes There are patches
> >> like Extend the max dotclock limit to WCL, Restrict max source rate
> >> for WCL to HBR3,
> >> drm/i915/wcl: Add display device info, Add power well mapping for WCL
> >> etc.
> >> git log shows under merge tag the "Add support for Wildcat Lake (WCL)
> >> display, version 30.02"
> >> So, could not find the patch for which I could mention fixes.
> >
> > Fixes: 632633d095b6 ("drm/i915/wcl: Add display device info")
> >
> > Should be sufficient.
> >
> 
> Sorry, support for the device id was added even before that.
> 
> Better fit.
> 
> Fixes: f8e1c3e07db1 ("drm/i915/xe3lpd: Add support for display version
> 30.02")
> 
> It would be worth checking though if these patches applies as is or might
> need some rebase.

Thank you Chaitanya. Will use this and float again.

Regards
Vidya

> 
> ==
> Chaitanya
> 
> >>
> >> Regards
> >> Vidya
> >>
> >>>
> >>>> Suggested-by: Charlton Lin <charlton.lin@intel.com>
> >>>> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> >>>> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> >>>> ---
> >>>>    drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
> >>>>    1 file changed, 2 insertions(+), 2 deletions(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> >>>> b/drivers/gpu/drm/i915/display/intel_dp.c
> >>>> index 00e02e019d25..ef164a797618 100644
> >>>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> >>>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> >>>> @@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp
> >>>> *intel_dp)
> >>>>                return false;
> >>>>        }
> >>>>
> >>>> -    return DISPLAY_VER(display) >= 12 ||
> >>>> +    return ((DISPLAY_VER(display) >= 12 &&
> >>>> +DISPLAY_VERx100(display) !=
> >>>> +3002) ||
> >>>>            (DISPLAY_VER(display) == 11 &&
> >>>> -         encoder->port != PORT_A);
> >>>> +         encoder->port != PORT_A));
> >>>>    }
> >>>>
> >>>>    static int dg2_max_source_rate(struct intel_dp *intel_dp)
> >>
> >

RE: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL

[Jani Nikula]

On Wed, 28 Oct 2026, "Srinivas, Vidya" <vidya.srinivas@intel.com> wrote:
>> -----Original Message-----
>> From: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
>> Sent: 28 October 2026 15:07
>> To: Srinivas, Vidya <vidya.srinivas@intel.com>; intel-gfx@lists.freedesktop.org
>> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
>> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Lin, Charlton
>> <charlton.lin@intel.com>
>> Subject: Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL
>> 
>> 
>> 
>> On 10/28/2026 2:58 PM, Borah, Chaitanya Kumar wrote:
>> >
>> >
>> > On 10/28/2026 2:27 PM, Srinivas, Vidya wrote:
>> >>
>> >>
>> >>> -----Original Message-----
>> >>> From: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
>> >>> Sent: 28 October 2026 14:08
>> >>> To: Srinivas, Vidya <vidya.srinivas@intel.com>; intel-
>> >>> gfx@lists.freedesktop.org
>> >>> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar,
>> >>> Uma <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Lin,
>> >>> Charlton <charlton.lin@intel.com>
>> >>> Subject: Re: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on
>> >>> WCL
>> >>>
>> >>>
>> >>>
>> >>> On 10/28/2026 12:34 PM, Vidya Srinivas wrote:
>> >>>> Pipe joining is not supported in the WCL display configuration.
>> >>>> Report no joiner support on WCL so that modes which would require
>> >>>> joining are rejected, matching the 4k 60Hz maximum resolution
>> >>>> documented for the platform.
>> >>>>
>> >>>> v2: Rebase onto latest upstream
>> >>>> v3: Fix up the commit message
>> >>>> v4: Split the scaler and joiner changes into separate patches
>> >>>> (Jani)
>> >>>>
>> >>>> Bspec: 74286
>> >>>> Cc: stable@vger.kernel.org
>> >>>
>> >>> Won't we need a Fixes tag to tell where this change need to go to?
>> >>
>> >> Hello Chaitanya,
>> >>
>> >> Thank you. Yes, I did check checkpatch gave the same warning but I
>> >> couldn’t find the exact patch to call out the fixes There are patches
>> >> like Extend the max dotclock limit to WCL, Restrict max source rate
>> >> for WCL to HBR3,
>> >> drm/i915/wcl: Add display device info, Add power well mapping for WCL
>> >> etc.
>> >> git log shows under merge tag the "Add support for Wildcat Lake (WCL)
>> >> display, version 30.02"
>> >> So, could not find the patch for which I could mention fixes.
>> >
>> > Fixes: 632633d095b6 ("drm/i915/wcl: Add display device info")
>> >
>> > Should be sufficient.
>> >
>> 
>> Sorry, support for the device id was added even before that.
>> 
>> Better fit.
>> 
>> Fixes: f8e1c3e07db1 ("drm/i915/xe3lpd: Add support for display version
>> 30.02")
>> 
>> It would be worth checking though if these patches applies as is or might
>> need some rebase.
>
> Thank you Chaitanya. Will use this and float again.

You *never* need to resend patches just to add git commit message
trailers.

Doing so means another round of CI and delay for absolutely nothing.

We apply patches using b4, and simply replying with the trailers is
enough to have them picked up.

BR,
Jani.


>
> Regards
> Vidya
>
>> 
>> ==
>> Chaitanya
>> 
>> >>
>> >> Regards
>> >> Vidya
>> >>
>> >>>
>> >>>> Suggested-by: Charlton Lin <charlton.lin@intel.com>
>> >>>> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
>> >>>> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
>> >>>> ---
>> >>>>    drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
>> >>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>> >>>>
>> >>>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>> >>>> b/drivers/gpu/drm/i915/display/intel_dp.c
>> >>>> index 00e02e019d25..ef164a797618 100644
>> >>>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> >>>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> >>>> @@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp
>> >>>> *intel_dp)
>> >>>>                return false;
>> >>>>        }
>> >>>>
>> >>>> -    return DISPLAY_VER(display) >= 12 ||
>> >>>> +    return ((DISPLAY_VER(display) >= 12 &&
>> >>>> +DISPLAY_VERx100(display) !=
>> >>>> +3002) ||
>> >>>>            (DISPLAY_VER(display) == 11 &&
>> >>>> -         encoder->port != PORT_A);
>> >>>> +         encoder->port != PORT_A));
>> >>>>    }
>> >>>>
>> >>>>    static int dg2_max_source_rate(struct intel_dp *intel_dp)
>> >>
>> >
>

-- 
Jani Nikula, Intel

RE: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL

[Srinivas, Vidya]

> -----Original Message-----
> From: Srinivas, Vidya <vidya.srinivas@intel.com>
> Sent: 28 October 2026 12:34
> To: intel-gfx@lists.freedesktop.org
> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Srinivas, Vidya
> <vidya.srinivas@intel.com>; Lin, Charlton <charlton.lin@intel.com>
> Subject: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL
> 
> Pipe joining is not supported in the WCL display configuration.
> Report no joiner support on WCL so that modes which would require joining
> are rejected, matching the 4k 60Hz maximum resolution documented for the
> platform.
> 
> v2: Rebase onto latest upstream
> v3: Fix up the commit message
> v4: Split the scaler and joiner changes into separate patches (Jani)

Thanks Jani and Chaitanya. Adding fixes tag:

Fixes: 632633d095b6 ("drm/i915/wcl: Add display device info")

> 
> Bspec: 74286
> Cc: stable@vger.kernel.org
> Suggested-by: Charlton Lin <charlton.lin@intel.com>
> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 00e02e019d25..ef164a797618 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
>  			return false;
>  	}
> 
> -	return DISPLAY_VER(display) >= 12 ||
> +	return ((DISPLAY_VER(display) >= 12 && DISPLAY_VERx100(display) !=
> +3002) ||
>  		(DISPLAY_VER(display) == 11 &&
> -		 encoder->port != PORT_A);
> +		 encoder->port != PORT_A));
>  }
> 
>  static int dg2_max_source_rate(struct intel_dp *intel_dp)
> --
> 2.45.2

RE: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL

[Srinivas, Vidya]

> -----Original Message-----
> From: Srinivas, Vidya
> Sent: 28 October 2026 21:29
> To: intel-gfx@lists.freedesktop.org
> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Lin, Charlton
> <Charlton.Lin@intel.com>
> Subject: RE: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL
> 
> 
> 
> > -----Original Message-----
> > From: Srinivas, Vidya <vidya.srinivas@intel.com>
> > Sent: 28 October 2026 12:34
> > To: intel-gfx@lists.freedesktop.org
> > Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar,
> > Uma <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Srinivas,
> > Vidya <vidya.srinivas@intel.com>; Lin, Charlton
> > <charlton.lin@intel.com>
> > Subject: [PATCH v4 2/2] drm/i915/display: Disable pipe joiner on WCL
> >
> > Pipe joining is not supported in the WCL display configuration.
> > Report no joiner support on WCL so that modes which would require
> > joining are rejected, matching the 4k 60Hz maximum resolution
> > documented for the platform.
> >
> > v2: Rebase onto latest upstream
> > v3: Fix up the commit message
> > v4: Split the scaler and joiner changes into separate patches (Jani)
> 
> Thanks Jani and Chaitanya. Adding fixes tag:
> 
> Fixes: 632633d095b6 ("drm/i915/wcl: Add display device info")
> 

  Sorry, since pipe auto-discovery via DFSM was already
  effective when 30.02 was enabled, the joiner was wrongly allowed from
  f8e1c3e07db1 onwards. Updating fixes tag:
 
  Fixes: f8e1c3e07db1 ("drm/i915/xe3lpd: Add support for display version 30.02")

> >
> > Bspec: 74286
> > Cc: stable@vger.kernel.org
> > Suggested-by: Charlton Lin <charlton.lin@intel.com>
> > Reviewed-by: Uma Shankar <uma.shankar@intel.com>
> > Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 00e02e019d25..ef164a797618 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -485,9 +485,9 @@ bool intel_dp_has_joiner(struct intel_dp *intel_dp)
> >  			return false;
> >  	}
> >
> > -	return DISPLAY_VER(display) >= 12 ||
> > +	return ((DISPLAY_VER(display) >= 12 && DISPLAY_VERx100(display) !=
> > +3002) ||
> >  		(DISPLAY_VER(display) == 11 &&
> > -		 encoder->port != PORT_A);
> > +		 encoder->port != PORT_A));
> >  }
> >
> >  static int dg2_max_source_rate(struct intel_dp *intel_dp)
> > --
> > 2.45.2

RE: [PATCH v4 0/2] drm/i915/display: Limit scaler count and disable pipe joiner on WCL

[Shankar, Uma]

> -----Original Message-----
> From: Srinivas, Vidya <vidya.srinivas@intel.com>
> Sent: Wednesday, October 28, 2026 12:34 PM
> To: intel-gfx@lists.freedesktop.org
> Cc: intel-xe@lists.freedesktop.org; stable@vger.kernel.org; Shankar, Uma
> <uma.shankar@intel.com>; jani.nikula@linux.intel.com; Srinivas, Vidya
> <vidya.srinivas@intel.com>
> Subject: [PATCH v4 0/2] drm/i915/display: Limit scaler count and disable pipe
> joiner on WCL
> 
> Pipe joining is not supported in the WCL display configuration.
> Modes that would require joining are rejected, matching the 4k 60Hz maximum
> resolution documented for the platform.
> 
> Also, WCL supports a single pipe scaler instead of two.

Pushed the changes to drm-intel-next. Thanks for the patches and reviews.
Have taken the correct Fixes: tag while merging, dropped others.

Regards,
Uma Shankar

> Vidya Srinivas (2):
>   drm/i915/display: Single scaler per pipe on WCL
>   drm/i915/display: Disable pipe joiner on WCL
> 
>  drivers/gpu/drm/i915/display/intel_display_device.c | 5 ++++-
>  drivers/gpu/drm/i915/display/intel_dp.c             | 4 ++--
>  2 files changed, 6 insertions(+), 3 deletions(-)
> 
> --
> 2.45.2