Re: [PATCH] media: tegra-video: Use BIT macro in tegra20.c

[Thierry Reding]

On Thu, Jul 23, 2026 at 01:18:11PM +0900, Mikko Perttunen wrote:
> On Thursday, July 23, 2026 12:40 AM Faisal Mukhtar wrote:
> > Fix checkpatch.pl warnings by replacing explicit
> > bit shift (1 << n) with the BIT macro, to better
> > adhere to the kernel coding style.
> > 
> > Signed-off-by: Faisal Mukhtar <mukhtarfaisal03@xxxxxxxxx>
> > ---
> >  drivers/staging/media/tegra-video/tegra20.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/staging/media/tegra-video/tegra20.c b/drivers/staging/media/tegra-video/tegra20.c
> > index e513e6ccb776..cdfd9f276d11 100644
> > --- a/drivers/staging/media/tegra-video/tegra20.c
> > +++ b/drivers/staging/media/tegra-video/tegra20.c
> > @@ -177,15 +177,15 @@ enum tegra_vi_out {
> >  #define       CSI_SKIP_PACKET_THRESHOLD(n)		(((n) & 0xff) << 16)
> >  #define TEGRA_CSI_PIXEL_STREAM_CONTROL0(n)		(0x0018 + (n) * 0x2c)
> >  #define       CSI_PP_PAD_FRAME_PAD0S			(0 << 28)
> > -#define       CSI_PP_PAD_FRAME_PAD1S			(1 << 28)
> > +#define       CSI_PP_PAD_FRAME_PAD1S			BIT(28)
> >  #define       CSI_PP_PAD_FRAME_NOPAD			(2 << 28)
> >  #define       CSI_PP_HEADER_EC_ENABLE			BIT(27)
> >  #define       CSI_PP_PAD_SHORT_LINE_PAD0S		(0 << 24)
> > -#define       CSI_PP_PAD_SHORT_LINE_PAD1S		(1 << 24)
> > +#define       CSI_PP_PAD_SHORT_LINE_PAD1S		BIT(24)
> >  #define       CSI_PP_PAD_SHORT_LINE_NOPAD		(2 << 24)
> >  #define       CSI_PP_EMBEDDED_DATA_EMBEDDED		BIT(20)
> >  #define       CSI_PP_OUTPUT_FORMAT_ARBITRARY		(0 << 16)
> > -#define       CSI_PP_OUTPUT_FORMAT_PIXEL		(1 << 16)
> > +#define       CSI_PP_OUTPUT_FORMAT_PIXEL		BIT(16)
> >  #define       CSI_PP_OUTPUT_FORMAT_PIXEL_REP		(2 << 16)
> >  #define       CSI_PP_OUTPUT_FORMAT_STORE		(3 << 16)
> >  #define       CSI_PP_VIRTUAL_CHANNEL_ID(n)		(((n) - 1) << 14)
> > -- 
> > 2.53.0
> > 
> > 
> 
> BIT is only used for true/false fields. These are not that.

The best way for silencing checkpatch would probably be to define fields
for each of these using GENMASK(), listing the values as defines without
any bitshift and then change the code to use FIELD_PREP(). Or define the
field values using FIELD_PREP() or FIELD_PREP_CONST().

Thierry

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