Re: [PATCH 1/1] drm/i915/dmc: Use drm_WARN_ONCE()

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Oct 15, 2025 at 03:50:42PM +0200, Petr Vorel wrote:
> assert_dmc_loaded() removed in 43175c92d4038 used drm_WARN_ONCE(),
> but new assert_dmc_loaded() use drm_WARN().
> 
> Log is already noise quite a lot due loop over dmc->dmc_info[dmc_id]
> array (76 logs on my machine), therefore use drm_WARN_ONCE().
> 
> Fixes: 43175c92d4038 ("drm/i915/dmc: Assert DMC is loaded harder")
> Signed-off-by: Petr Vorel <pvorel@suse.cz>
> ---
> Ville, am I wrong and it's really needed to see all the oops for the
> threads?

Kinda irrelevant because this should never happen. So the real
question we need to ask is why are you seeing this at all?

Please file a bug at
https://gitlab.freedesktop.org/drm/i915/kernel/-/issues
and attch the full dmesg with drm.debug=0xe passed to the kernel
cmdline.

> 
> Kind regards,
> Petr
> 
>  drivers/gpu/drm/i915/display/intel_dmc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c
> index 517bebb0b4aac..53db7279c7c99 100644
> --- a/drivers/gpu/drm/i915/display/intel_dmc.c
> +++ b/drivers/gpu/drm/i915/display/intel_dmc.c
> @@ -626,7 +626,7 @@ static void assert_dmc_loaded(struct intel_display *display,
>  	found = intel_de_read(display, DMC_PROGRAM(dmc->dmc_info[dmc_id].start_mmioaddr, 0));
>  	expected = dmc->dmc_info[dmc_id].payload[0];
>  
> -	drm_WARN(display->drm, found != expected,
> +	drm_WARN_ONCE(display->drm, found != expected,
>  		 "DMC %d program storage start incorrect (expected 0x%x, current 0x%x)\n",
>  		 dmc_id, expected, found);
>  
> @@ -642,7 +642,7 @@ static void assert_dmc_loaded(struct intel_display *display,
>  			expected &= ~DMC_EVT_CTL_ENABLE;
>  		}
>  
> -		drm_WARN(display->drm, found != expected,
> +		drm_WARN_ONCE(display->drm, found != expected,
>  			 "DMC %d mmio[%d]/0x%x incorrect (expected 0x%x, current 0x%x)\n",
>  			 dmc_id, i, i915_mmio_reg_offset(reg), expected, found);
>  	}
> -- 
> 2.51.0

-- 
Ville Syrjälä
Intel