[PATCH 11/21] drivers: don't use GENMASK() in FIELD_PREP_WM16()

[Mark Brown]

On Sat, Oct 25, 2025 at 12:40:10PM -0400, Yury Norov (NVIDIA) wrote:

> Recently added FIELD_PREP_WM16() in a few places uses GENMASK. It's
> confusing and may mislead readers. Switch to BITS() or FIRST_BITS()
> as appropriate.

This doesn't seem to line up with the actual change, you're not altering
FIELD_PREP_WM16() at all but rather altering things that use it.

As mentioned in submitting-patches.rst when submitting a patch series
you should supply a cover letter for that patch series which describes
the overall content of the series.  This helps people understand what
they are looking at and how things fit together.

> ---
>  drivers/gpu/drm/rockchip/rockchip_lvds.h             | 2 +-
>  drivers/gpu/drm/rockchip/rockchip_vop2_reg.c         | 4 ++--
>  drivers/media/platform/synopsys/hdmirx/snps_hdmirx.h | 4 ++--
>  drivers/mmc/host/dw_mmc-rockchip.c                   | 4 ++--
>  drivers/soc/rockchip/grf.c                           | 4 ++--
>  sound/soc/rockchip/rockchip_i2s_tdm.h                | 2 +-
>  6 files changed, 10 insertions(+), 10 deletions(-)

It doesn't help to send changes to unrelated subsystems in one patch
either...

> --- a/sound/soc/rockchip/rockchip_i2s_tdm.h
> +++ b/sound/soc/rockchip/rockchip_i2s_tdm.h
> @@ -287,7 +287,7 @@ enum {
>  #define I2S_TDM_RXCR	(0x0034)
>  #define I2S_CLKDIV	(0x0038)
>  
> -#define HIWORD_UPDATE(v, h, l)	(FIELD_PREP_WM16_CONST(GENMASK((h), (l)), (v)))
> +#define HIWORD_UPDATE(v, h, l)	(FIELD_PREP_WM16_CONST(BITS((l), (h)), (v)))

This is adjusting the implementation of something that takes in h, l to
use l, h which if anything seems likely to introduce confusion, and
definitely feels well into bikeshed territory.  I don't *super* care but
I'm having a hard time seeing the benefit.
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