diff mbox series

[v3] drm/i915/display: WA for Re-initialize dispcnlunitt1 xosc clock

Message ID 20240619103803.865289-1-mitulkumar.ajitkumar.golani@intel.com (mailing list archive)
State New, archived
Headers show
Series [v3] drm/i915/display: WA for Re-initialize dispcnlunitt1 xosc clock | expand

Commit Message

Mitul Golani June 19, 2024, 10:38 a.m. UTC
The dispcnlunit1_cp_xosc_clk should be de-asserted in display off
and only asserted in display on. But during observation it found
clk remains active in display OFF. As workaround, Display driver
shall execute set-reset sequence at the end of the Initialize
Sequence.

Wa_15013987218

Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display_power.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Nemesa Garg June 20, 2024, 4:36 a.m. UTC | #1
> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@lists.freedesktop.org> On Behalf Of Mitul
> Golani
> Sent: Wednesday, June 19, 2024 4:08 PM
> To: intel-gfx@lists.freedesktop.org
> Subject: [PATCH v3] drm/i915/display: WA for Re-initialize dispcnlunitt1 xosc clock
> 
> The dispcnlunit1_cp_xosc_clk should be de-asserted in display off and only
> asserted in display on. But during observation it found clk remains active in display
> OFF. As workaround, Display driver shall execute set-reset sequence at the end of
> the Initialize Sequence.
> 
> Wa_15013987218
> 
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
Reviewed-by: Nemesa Garg <nemesa.garg@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_power.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
> b/drivers/gpu/drm/i915/display/intel_display_power.c
> index e288a1b21d7e..aef54c1a2ba9 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -1704,6 +1704,14 @@ static void icl_display_core_init(struct
> drm_i915_private *dev_priv,
>  	/* Wa_14011503030:xelpd */
>  	if (DISPLAY_VER(dev_priv) == 13)
>  		intel_de_write(dev_priv, XELPD_DISPLAY_ERR_FATAL_MASK,
> ~0);
> +
> +	/* Wa_15013987218 */
> +	if (DISPLAY_VER(dev_priv) == 20) {
> +		intel_de_write(dev_priv, SOUTH_DSPCLK_GATE_D,
> +			       PCH_GMBUSUNIT_CLOCK_GATE_DISABLE);

Nit:  we can replace the above statement with this intel_de_rmw(dev_priv, SOUTH_DSPCLK_GATE_D, 0, PCH_GMBUSUNIT_CLOCK_GATE_DISABLE) so that code consistency can be maintained in the code block.
otherwise LGTM.

> +		intel_de_rmw(dev_priv, SOUTH_DSPCLK_GATE_D,
> +			     PCH_GMBUSUNIT_CLOCK_GATE_DISABLE, 0);
> +	}
>  }
> 
>  static void icl_display_core_uninit(struct drm_i915_private *dev_priv)
> --
> 2.45.2
Jani Nikula June 20, 2024, 1:36 p.m. UTC | #2
On Thu, 20 Jun 2024, "Garg, Nemesa" <nemesa.garg@intel.com> wrote:
>> -----Original Message-----
>> From: Intel-gfx <intel-gfx-bounces@lists.freedesktop.org> On Behalf Of Mitul
>> Golani
>> Sent: Wednesday, June 19, 2024 4:08 PM
>> To: intel-gfx@lists.freedesktop.org
>> Subject: [PATCH v3] drm/i915/display: WA for Re-initialize dispcnlunitt1 xosc clock
>> 
>> The dispcnlunit1_cp_xosc_clk should be de-asserted in display off and only
>> asserted in display on. But during observation it found clk remains active in display
>> OFF. As workaround, Display driver shall execute set-reset sequence at the end of
>> the Initialize Sequence.
>> 
>> Wa_15013987218
>> 
>> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
> Reviewed-by: Nemesa Garg <nemesa.garg@intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_display_power.c | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
>> b/drivers/gpu/drm/i915/display/intel_display_power.c
>> index e288a1b21d7e..aef54c1a2ba9 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
>> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
>> @@ -1704,6 +1704,14 @@ static void icl_display_core_init(struct
>> drm_i915_private *dev_priv,
>>  	/* Wa_14011503030:xelpd */
>>  	if (DISPLAY_VER(dev_priv) == 13)
>>  		intel_de_write(dev_priv, XELPD_DISPLAY_ERR_FATAL_MASK,
>> ~0);
>> +
>> +	/* Wa_15013987218 */
>> +	if (DISPLAY_VER(dev_priv) == 20) {
>> +		intel_de_write(dev_priv, SOUTH_DSPCLK_GATE_D,
>> +			       PCH_GMBUSUNIT_CLOCK_GATE_DISABLE);
>
> Nit:  we can replace the above statement with this intel_de_rmw(dev_priv, SOUTH_DSPCLK_GATE_D, 0, PCH_GMBUSUNIT_CLOCK_GATE_DISABLE) so that code consistency can be maintained in the code block.
> otherwise LGTM.

It's not just about consistency. Are you even sure you can erase
everything else in the register here?

BR,
Jani.

>
>> +		intel_de_rmw(dev_priv, SOUTH_DSPCLK_GATE_D,
>> +			     PCH_GMBUSUNIT_CLOCK_GATE_DISABLE, 0);
>> +	}
>>  }
>> 
>>  static void icl_display_core_uninit(struct drm_i915_private *dev_priv)
>> --
>> 2.45.2
>
Suraj Kandpal July 8, 2024, 4:17 a.m. UTC | #3
> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@lists.freedesktop.org> On Behalf Of Mitul
> Golani
> Sent: Wednesday, June 19, 2024 4:08 PM
> To: intel-gfx@lists.freedesktop.org
> Subject: [PATCH v3] drm/i915/display: WA for Re-initialize dispcnlunitt1 xosc
> clock
> 
> The dispcnlunit1_cp_xosc_clk should be de-asserted in display off and only
> asserted in display on. But during observation it found clk remains active in
> display OFF. As workaround, Display driver shall execute set-reset sequence at
> the end of the Initialize Sequence.
> 
> Wa_15013987218
> 

No need to explain the problem just the solution and what you are doing in
The patch
Also Nit:
Write above as HSD: 15013987218

Regards,
Suraj Kandpal
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_power.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c
> b/drivers/gpu/drm/i915/display/intel_display_power.c
> index e288a1b21d7e..aef54c1a2ba9 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -1704,6 +1704,14 @@ static void icl_display_core_init(struct
> drm_i915_private *dev_priv,
>  	/* Wa_14011503030:xelpd */
>  	if (DISPLAY_VER(dev_priv) == 13)
>  		intel_de_write(dev_priv, XELPD_DISPLAY_ERR_FATAL_MASK,
> ~0);
> +
> +	/* Wa_15013987218 */
> +	if (DISPLAY_VER(dev_priv) == 20) {
> +		intel_de_write(dev_priv, SOUTH_DSPCLK_GATE_D,
> +			       PCH_GMBUSUNIT_CLOCK_GATE_DISABLE);
> +		intel_de_rmw(dev_priv, SOUTH_DSPCLK_GATE_D,
> +			     PCH_GMBUSUNIT_CLOCK_GATE_DISABLE, 0);
> +	}
>  }
> 
>  static void icl_display_core_uninit(struct drm_i915_private *dev_priv)
> --
> 2.45.2
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index e288a1b21d7e..aef54c1a2ba9 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -1704,6 +1704,14 @@  static void icl_display_core_init(struct drm_i915_private *dev_priv,
 	/* Wa_14011503030:xelpd */
 	if (DISPLAY_VER(dev_priv) == 13)
 		intel_de_write(dev_priv, XELPD_DISPLAY_ERR_FATAL_MASK, ~0);
+
+	/* Wa_15013987218 */
+	if (DISPLAY_VER(dev_priv) == 20) {
+		intel_de_write(dev_priv, SOUTH_DSPCLK_GATE_D,
+			       PCH_GMBUSUNIT_CLOCK_GATE_DISABLE);
+		intel_de_rmw(dev_priv, SOUTH_DSPCLK_GATE_D,
+			     PCH_GMBUSUNIT_CLOCK_GATE_DISABLE, 0);
+	}
 }
 
 static void icl_display_core_uninit(struct drm_i915_private *dev_priv)