On 1.11.2017 15:03, Mauro Carvalho Chehab wrote:
> Hi Todor,
>
> Em Wed, 1 Nov 2017 14:38:02 +0200
> Todor Tomov <todor.tomov@xxxxxxxxxx> escreveu:
>
>> Hi Mauro,
>>
>> Thank you for pointing to this.
>>
>> On 1.11.2017 14:16, Mauro Carvalho Chehab wrote:
>>> if output->wm_num is bigger than 1, the value for reg is
>> If output->wn_num equals 2, we handle all cases (i == 0, i == 1) and set reg properly.
>> If output->wn_num is bigger than 2, then reg will not be initialized. However this is something that "cannot happen" and because of this the case is not handled.
>>
>> So I think that there is nothing wrong really but we have to do something to remove the warning. I agree with your patch, it is technically not a right value for reg but any cases in which wm_num is bigger than 2 are not supported anyway and should not happen.
>
> Thanks for your promptly answer. Well, if i is always at the [0..1] range,
> then I guess the enclosed patch is actually better.
I don't think that there is a lot of difference practically. If this one fixes the warning too, then it is fine for me. Thank you for working on this.
Best regards,
Todor
>
>
> Thanks,
> Mauro
>
>
> [PATCH] media: camss-vfe: always initialize reg at vfe_set_xbar_cfg()
>
> if output->wm_num is bigger than 2, the value for reg is
> not initialized, as warned by smatch:
> drivers/media/platform/qcom/camss-8x16/camss-vfe.c:633 vfe_set_xbar_cfg() error: uninitialized symbol 'reg'.
> drivers/media/platform/qcom/camss-8x16/camss-vfe.c:637 vfe_set_xbar_cfg() error: uninitialized symbol 'reg'.
>
> That shouldn't happen in practice, so add a logic that will
> break the loop if i > 1, fixing the warnings.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
>
> diff --git a/drivers/media/platform/qcom/camss-8x16/camss-vfe.c b/drivers/media/platform/qcom/camss-8x16/camss-vfe.c
> index b22d2dfcd3c2..55232a912950 100644
> --- a/drivers/media/platform/qcom/camss-8x16/camss-vfe.c
> +++ b/drivers/media/platform/qcom/camss-8x16/camss-vfe.c
> @@ -622,6 +622,9 @@ static void vfe_set_xbar_cfg(struct vfe_device *vfe, struct vfe_output *output,
> reg = VFE_0_BUS_XBAR_CFG_x_M_PAIR_STREAM_EN;
> if (p == V4L2_PIX_FMT_NV12 || p == V4L2_PIX_FMT_NV16)
> reg |= VFE_0_BUS_XBAR_CFG_x_M_PAIR_STREAM_SWAP_INTER_INTRA;
> + } else {
> + /* On current devices output->wm_num is always <= 2 */
> + break;
> }
>
> if (output->wm_idx[i] % 2 == 1)
>
