[PATCH v4 2/4] drm/i915/display: don't allow DMC wakelock on older hardware

[Shankar, Uma]

> -----Original Message-----
> From: Coelho, Luciano <luciano.coelho at intel.com>
> Sent: Thursday, April 4, 2024 5:12 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: intel-xe at lists.freedesktop.org; Shankar, Uma <uma.shankar at intel.com>;
> ville.syrjala at linux.intel.com; Nikula, Jani <jani.nikula at intel.com>
> Subject: [PATCH v4 2/4] drm/i915/display: don't allow DMC wakelock on older
> hardware
> 
> Only allow running DMC wakelock code if the display version is 20 or greater.  Also
> check if DMC is loaded before enabling.

Looks Good to me.
Reviewed-by: Uma Shankar <uma.shankar at intel.com>

> Signed-off-by: Luca Coelho <luciano.coelho at intel.com>
> ---
>  .../drm/i915/display/intel_display_driver.c   |  1 +
>  drivers/gpu/drm/i915/display/intel_dmc_wl.c   | 26 +++++++++++++++++++
>  2 files changed, 27 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_driver.c
> b/drivers/gpu/drm/i915/display/intel_display_driver.c
> index 87dd07e0d138..e4015557af6a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_driver.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_driver.c
> @@ -198,6 +198,7 @@ void intel_display_driver_early_probe(struct
> drm_i915_private *i915)
>  	intel_dpll_init_clock_hook(i915);
>  	intel_init_display_hooks(i915);
>  	intel_fdi_init_hook(i915);
> +	intel_dmc_wl_init(i915);
>  }
> 
>  /* part #1: call before irq install */
> diff --git a/drivers/gpu/drm/i915/display/intel_dmc_wl.c
> b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
> index 3d7cf47321c2..065652fc475c 100644
> --- a/drivers/gpu/drm/i915/display/intel_dmc_wl.c
> +++ b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
> @@ -6,6 +6,7 @@
>  #include <linux/kernel.h>
> 
>  #include "intel_de.h"
> +#include "intel_dmc.h"
>  #include "intel_dmc_regs.h"
>  #include "intel_dmc_wl.h"
> 
> @@ -110,10 +111,23 @@ static bool intel_dmc_wl_check_range(u32 address)
>  	return wl_needed;
>  }
> 
> +static bool __intel_dmc_wl_supported(struct drm_i915_private *i915) {
> +	if (DISPLAY_VER(i915) < 20 ||
> +	    !intel_dmc_has_payload(i915))
> +		return false;
> +
> +	return true;
> +}
> +
>  void intel_dmc_wl_init(struct drm_i915_private *i915)  {
>  	struct intel_dmc_wl *wl = &i915->display.wl;
> 
> +	/* don't call __intel_dmc_wl_supported(), DMC is not loaded yet */
> +	if (DISPLAY_VER(i915) < 20)
> +		return;
> +
>  	INIT_DELAYED_WORK(&wl->work, intel_dmc_wl_work);
>  	spin_lock_init(&wl->lock);
>  	refcount_set(&wl->refcount, 0);
> @@ -124,6 +138,9 @@ void intel_dmc_wl_enable(struct drm_i915_private
> *i915)
>  	struct intel_dmc_wl *wl = &i915->display.wl;
>  	unsigned long flags;
> 
> +	if (!__intel_dmc_wl_supported(i915))
> +		return;
> +
>  	spin_lock_irqsave(&wl->lock, flags);
> 
>  	if (wl->enabled)
> @@ -148,6 +165,9 @@ void intel_dmc_wl_disable(struct drm_i915_private
> *i915)
>  	struct intel_dmc_wl *wl = &i915->display.wl;
>  	unsigned long flags;
> 
> +	if (!__intel_dmc_wl_supported(i915))
> +		return;
> +
>  	flush_delayed_work(&wl->work);
> 
>  	spin_lock_irqsave(&wl->lock, flags);
> @@ -171,6 +191,9 @@ void intel_dmc_wl_get(struct drm_i915_private *i915,
> i915_reg_t reg)
>  	struct intel_dmc_wl *wl = &i915->display.wl;
>  	unsigned long flags;
> 
> +	if (!__intel_dmc_wl_supported(i915))
> +		return;
> +
>  	if (!intel_dmc_wl_check_range(reg.reg))
>  		return;
> 
> @@ -215,6 +238,9 @@ void intel_dmc_wl_put(struct drm_i915_private *i915,
> i915_reg_t reg)
>  	struct intel_dmc_wl *wl = &i915->display.wl;
>  	unsigned long flags;
> 
> +	if (!__intel_dmc_wl_supported(i915))
> +		return;
> +
>  	if (!intel_dmc_wl_check_range(reg.reg))
>  		return;
> 
> --
> 2.39.2