Re: [PATCH v2 1/2] drm/i915/display: avoid logging DC3CO transitions

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] drm/i915/display: per-frame DC3CO entry log left in
  xe3lpd_enable_dc3co()
--

commit 168565af43c727ae42413d9678ac0afa5023d467
Author: Dibin Moolakadan Subrahmanian <dibin.moolakadan.subrahmanian@intel.com>

drm/i915/display: avoid logging DC3CO transitions

This commit suppresses per-frame DC3CO transition debug messages in
gen9_set_dc_state() and logs DC3CO trigger changes in
intel_display_power_dc3co_update().

> diff --git a/drivers/gpu/drm/i915/display/intel_display_power_well.c b/drivers/gpu/drm/i915/display/intel_display_power_well.c
> index 233465a8306ec..6d07643fc14fa 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power_well.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power_well.c
> @@ -862,8 +862,18 @@ void gen9_set_dc_state(struct intel_display *display, u32 state)
>  
>  	val = intel_de_read(display, DC_STATE_EN);
>  	mask = gen9_dc_mask(display);
> -	drm_dbg_kms(display->drm, "Setting DC state from %02x to %02x\n",
> -		    val & mask, state);
> +
> +	/*
> +	 * DC3co is entered and exited once per frame while PSR2 or panel
> +	 * replay is active, so logging both transitions floods the log. The
> +	 * exit additionally happens from intel_display_power_get(DC_OFF) in
> +	 * the atomic commit path, before the flip has been armed, where the
> +	 * printk is a measurable part of the time budget. Skip both.
> +	 */
> +	if ((val & mask) != DC_STATE_EN_UPTO_DC3CO &&
> +	    state != DC_STATE_EN_UPTO_DC3CO)
> +		drm_dbg_kms(display->drm, "Setting DC state from %02x to %02x\n",
> +			    val & mask, state);

[Severity: Low]
Should the drm_dbg_kms() call in xe3lpd_enable_dc3co() also be removed?

xe3lpd_enable_dc3co() is the sole caller passing DC_STATE_EN_UPTO_DC3CO to
gen9_set_dc_state(), and it still logs "Enabling DC3CO" on every frame
when entering DC3CO:

drivers/gpu/drm/i915/display/intel_display_power_well.c:xe3lpd_enable_dc3co() {
	assert_can_enable_dc3co(display);
	drm_dbg_kms(display->drm, "Enabling DC3CO\n");
	intel_dmc_wl_enable(display, DC_STATE_EN_UPTO_DC3CO);
	gen9_set_dc_state(display, DC_STATE_EN_UPTO_DC3CO);
}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261111075105.2166760-4-dibin.moolakadan.subrahmanian@intel.com?part=1