Re: [PATCH 05/11] cx25840/cx18: Use standard ordering of mask and shift

From: Andy Walls
Date: Sat Nov 08 2014 - 09:34:19 EST


On Sun, 2014-10-26 at 22:25 -0700, Joe Perches wrote:
> Precedence of & and >> is not the same and is not left to right.
> shift has higher precedence and should be done after the mask.
>
> This use has a mask then shift which is not the normal style.
>
> Move the shift before the mask to match nearly all the other
> uses in kernel.
>
> Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>

The patch is technically correct.

Reviewed-by: Andy Walls <awalls@xxxxxxxxxxxxxxxx>

> ---
> drivers/media/i2c/cx25840/cx25840-core.c | 12 ++++++------
> drivers/media/pci/cx18/cx18-av-core.c | 16 ++++++++--------
> 2 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/media/i2c/cx25840/cx25840-core.c b/drivers/media/i2c/cx25840/cx25840-core.c
> index e453a3f..0327032 100644
> --- a/drivers/media/i2c/cx25840/cx25840-core.c
> +++ b/drivers/media/i2c/cx25840/cx25840-core.c
> @@ -879,7 +879,7 @@ void cx25840_std_setup(struct i2c_client *client)
> /* Sets horizontal blanking delay and active lines */
> cx25840_write(client, 0x470, hblank);
> cx25840_write(client, 0x471,
> - 0xff & (((hblank >> 8) & 0x3) | (hactive << 4)));
> + (((hblank >> 8) & 0x3) | (hactive << 4)) & 0xff);
> cx25840_write(client, 0x472, hactive >> 4);
>
> /* Sets burst gate delay */
> @@ -888,13 +888,13 @@ void cx25840_std_setup(struct i2c_client *client)
> /* Sets vertical blanking delay and active duration */
> cx25840_write(client, 0x474, vblank);
> cx25840_write(client, 0x475,
> - 0xff & (((vblank >> 8) & 0x3) | (vactive << 4)));
> + (((vblank >> 8) & 0x3) | (vactive << 4)) & 0xff);
> cx25840_write(client, 0x476, vactive >> 4);
> cx25840_write(client, 0x477, vblank656);
>
> /* Sets src decimation rate */
> - cx25840_write(client, 0x478, 0xff & src_decimation);
> - cx25840_write(client, 0x479, 0xff & (src_decimation >> 8));
> + cx25840_write(client, 0x478, src_decimation & 0xff);
> + cx25840_write(client, 0x479, (src_decimation >> 8) & 0xff);
>
> /* Sets Luma and UV Low pass filters */
> cx25840_write(client, 0x47a, luma_lpf << 6 | ((uv_lpf << 4) & 0x30));
> @@ -904,8 +904,8 @@ void cx25840_std_setup(struct i2c_client *client)
>
> /* Sets SC Step*/
> cx25840_write(client, 0x47c, sc);
> - cx25840_write(client, 0x47d, 0xff & sc >> 8);
> - cx25840_write(client, 0x47e, 0xff & sc >> 16);
> + cx25840_write(client, 0x47d, (sc >> 8) & 0xff);
> + cx25840_write(client, 0x47e, (sc >> 16) & 0xff);
>
> /* Sets VBI parameters */
> if (std & V4L2_STD_625_50) {
> diff --git a/drivers/media/pci/cx18/cx18-av-core.c b/drivers/media/pci/cx18/cx18-av-core.c
> index 2d3afe0..45be26c 100644
> --- a/drivers/media/pci/cx18/cx18-av-core.c
> +++ b/drivers/media/pci/cx18/cx18-av-core.c
> @@ -490,8 +490,8 @@ void cx18_av_std_setup(struct cx18 *cx)
>
> /* Sets horizontal blanking delay and active lines */
> cx18_av_write(cx, 0x470, hblank);
> - cx18_av_write(cx, 0x471, 0xff & (((hblank >> 8) & 0x3) |
> - (hactive << 4)));
> + cx18_av_write(cx, 0x471,
> + (((hblank >> 8) & 0x3) | (hactive << 4)) & 0xff);
> cx18_av_write(cx, 0x472, hactive >> 4);
>
> /* Sets burst gate delay */
> @@ -499,14 +499,14 @@ void cx18_av_std_setup(struct cx18 *cx)
>
> /* Sets vertical blanking delay and active duration */
> cx18_av_write(cx, 0x474, vblank);
> - cx18_av_write(cx, 0x475, 0xff & (((vblank >> 8) & 0x3) |
> - (vactive << 4)));
> + cx18_av_write(cx, 0x475,
> + (((vblank >> 8) & 0x3) | (vactive << 4)) & 0xff);
> cx18_av_write(cx, 0x476, vactive >> 4);
> cx18_av_write(cx, 0x477, vblank656);
>
> /* Sets src decimation rate */
> - cx18_av_write(cx, 0x478, 0xff & src_decimation);
> - cx18_av_write(cx, 0x479, 0xff & (src_decimation >> 8));
> + cx18_av_write(cx, 0x478, src_decimation & 0xff);
> + cx18_av_write(cx, 0x479, (src_decimation >> 8) & 0xff);
>
> /* Sets Luma and UV Low pass filters */
> cx18_av_write(cx, 0x47a, luma_lpf << 6 | ((uv_lpf << 4) & 0x30));
> @@ -516,8 +516,8 @@ void cx18_av_std_setup(struct cx18 *cx)
>
> /* Sets SC Step*/
> cx18_av_write(cx, 0x47c, sc);
> - cx18_av_write(cx, 0x47d, 0xff & sc >> 8);
> - cx18_av_write(cx, 0x47e, 0xff & sc >> 16);
> + cx18_av_write(cx, 0x47d, (sc >> 8) & 0xff);
> + cx18_av_write(cx, 0x47e, (sc >> 16) & 0xff);
>
> if (std & V4L2_STD_625_50) {
> state->slicer_line_delay = 1;


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