media: iris: Fix fps calculation

iris_venc_s_param() uses do_div to divide two 64 bits operators, this is
wrong. Luckily for us, both of the operators fit in 32 bits, so we can use
a normal division.

Now that we are at it, mark the fps smaller than 1 as invalid, the code
does not seem to handle them properly.

The following cocci warning is fixed with this patch:
./platform/qcom/iris/iris_venc.c:378:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead

Fixes: 4ff586ff28e3 ("media: iris: Add support for G/S_PARM for encoder video device")
Reviewed-by: Dikshita Agarwal <dikshita.agarwal@oss.qualcomm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/media/platform/qcom/iris/iris_venc.c b/drivers/media/platform/qcom/iris/iris_venc.c
index 5830eba93c68b27fa9db87bac63a691eaca338d2..0ed5018f9fe3326f5bcc1678e854589c65e8a954 100644 (file)
--- a/drivers/media/platform/qcom/iris/iris_venc.c
+++ b/drivers/media/platform/qcom/iris/iris_venc.c
@@ -382,8 +382,7 @@ int iris_venc_s_param(struct iris_inst *inst, struct v4l2_streamparm *s_parm)
        struct v4l2_fract *timeperframe = NULL;
        u32 default_rate = DEFAULT_FPS;
        bool is_frame_rate = false;
-       u64 us_per_frame, fps;
-       u32 max_rate;
+       u32 fps, max_rate;
 
        int ret = 0;
 
@@ -405,23 +404,19 @@ int iris_venc_s_param(struct iris_inst *inst, struct v4l2_streamparm *s_parm)
                        timeperframe->denominator = default_rate;
        }
 
-       us_per_frame = timeperframe->numerator * (u64)USEC_PER_SEC;
-       do_div(us_per_frame, timeperframe->denominator);
-
-       if (!us_per_frame)
+       fps = timeperframe->denominator / timeperframe->numerator;
+       if (!fps)
                return -EINVAL;
 
-       fps = (u64)USEC_PER_SEC;
-       do_div(fps, us_per_frame);
        if (fps > max_rate) {
                ret = -ENOMEM;
                goto reset_rate;
        }
 
        if (is_frame_rate)
-               inst->frame_rate = (u32)fps;
+               inst->frame_rate = fps;
        else
-               inst->operating_rate = (u32)fps;
+               inst->operating_rate = fps;
 
        if ((s_parm->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE && vb2_is_streaming(src_q)) ||
            (s_parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE && vb2_is_streaming(dst_q))) {