Re: [Intel-gfx] [PATCH] drm/i915/hwmon: Fix static analysis tool errors in i915 hwmon

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

On Wed, 29 Nov 2023, Karthik Poosa <karthik.poosa@intel.com> wrote:
> Updated i915 hwmon with fixes for issues reported by static analysis tool.

What's the problem? It's not enough to say this fixes a static analyzer
report. Tell us what the problem is, and why this is the fix.

BR,
Jani.


>
> Signed-off-by: Karthik Poosa <karthik.poosa@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_hwmon.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
> index 975da8e7f2a9..69bb49a684b6 100644
> --- a/drivers/gpu/drm/i915/i915_hwmon.c
> +++ b/drivers/gpu/drm/i915/i915_hwmon.c
> @@ -175,7 +175,7 @@ hwm_power1_max_interval_show(struct device *dev, struct device_attribute *attr,
>  	 *     tau4 = (4 | x) << y
>  	 * but add 2 when doing the final right shift to account for units
>  	 */
> -	tau4 = ((1 << x_w) | x) << y;
> +	tau4 = ((u64)(1 << x_w) | x) << y;
>  	/* val in hwmon interface units (millisec) */
>  	out = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w);
>  
> @@ -211,7 +211,7 @@ hwm_power1_max_interval_store(struct device *dev,
>  	r = FIELD_PREP(PKG_MAX_WIN, PKG_MAX_WIN_DEFAULT);
>  	x = REG_FIELD_GET(PKG_MAX_WIN_X, r);
>  	y = REG_FIELD_GET(PKG_MAX_WIN_Y, r);
> -	tau4 = ((1 << x_w) | x) << y;
> +	tau4 = ((u64)(1 << x_w) | x) << y;
>  	max_win = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w);
>  
>  	if (val > max_win)

-- 
Jani Nikula, Intel