[PATCH] scsi: ufs: exynos: fix programming of HCI_UTRL_NEXUS_TYPE

[Peter Griffin]

On Mon, 7 Jul 2025 at 18:05, André Draszik <andre.draszik at linaro.org> wrote:
>
> On Google gs101, the number of UTP transfer request slots (nutrs) is
> 32, and in this case the driver ends up programming the UTRL_NEXUS_TYPE
> incorrectly as 0.
>
> This is because the left hand side of the shift is 1, which is of type
> int, i.e. 31 bits wide. Shifting by more than that width results in
> undefined behaviour.
>
> Fix this by switching to the BIT() macro, which applies correct type
> casting as required. This ensures the correct value is written to
> UTRL_NEXUS_TYPE (0xffffffff on gs101), and it also fixes a UBSAN shift
> warning:
>     UBSAN: shift-out-of-bounds in drivers/ufs/host/ufs-exynos.c:1113:21
>     shift exponent 32 is too large for 32-bit type 'int'
>
> For consistency, apply the same change to the nutmrs / UTMRL_NEXUS_TYPE
> write.
>
> Fixes: 55f4b1f73631 ("scsi: ufs: ufs-exynos: Add UFS host support for Exynos SoCs")
> Cc: stable at vger.kernel.org
> Signed-off-by: André Draszik <andre.draszik at linaro.org>
> ---

Reviewed-by: Peter Griffin <peter.griffin at linaro.org>