Re: [PATCH] drm/i915/power: fix size for for_each_set_bit() in abox iteration

[Jani Nikula <jani.nikula@intel.com>]

On Fri, 05 Sep 2025, Matt Roper <matthew.d.roper@intel.com> wrote:
> On Fri, Sep 05, 2025 at 01:41:49PM +0300, Jani Nikula wrote:
>> for_each_set_bit() expects size to be in bits, not bytes. The abox mask
>> iteration uses bytes, but it works by coincidence, because the local
>> variable holding the mask is unsigned long, and the mask only ever has
>> bit 2 as the highest bit. Using a smaller type could lead to subtle and
>> very hard to track bugs.
>> 
>> Fixes: 62afef2811e4 ("drm/i915/rkl: RKL uses ABOX0 for pixel transfers")
>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
>> Cc: Matt Roper <matthew.d.roper@intel.com>
>> Cc: <stable@vger.kernel.org> # v5.9+
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>
> Good catch.
>
> Reviewed-by: Matt Roper <matthew.d.roper@intel.com>

Thanks, pushed to din.

BR,
Jani.

-- 
Jani Nikula, Intel