Re: [PATCH] drm/i915: encourage BIT() macro usage in register definitions

From: Rodrigo Vivi <rodrigo.vivi@intel.com>
To: Jani Nikula <jani.nikula@intel.com>
Cc: intel-gfx@lists.freedesktop.org, Paulo Zanoni <paulo.r.zanoni@intel.com>
Subject: Re: [PATCH] drm/i915: encourage BIT() macro usage in register definitions
Date: Wed, 27 Jun 2018 21:57:49 -0700	[thread overview]
Message-ID: <20180628045749.GH9765@intel.com> (raw)
In-Reply-To: <20180627144113.6989-1-jani.nikula@intel.com>

On Wed, Jun 27, 2018 at 05:41:13PM +0300, Jani Nikula wrote:
> There's already some BIT() usage here and there, embrace it.
> 
> Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 476118f46cf3..64b9c270045d 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -65,9 +65,10 @@
>   * but do note that the macros may be needed to read as well as write the
>   * register contents.
>   *
> - * Define bits using ``(1 << N)`` instead of ``BIT(N)``. We may change this in
> - * the future, but this is the prevailing style. Do **not** add ``_BIT`` suffix
> - * to the name.
> + * Define bits using ``BIT(N)`` instead of ``(1 << N)``. Do **not** add ``_BIT``
> + * suffix to the name. Exception to ``BIT()`` usage: Value 1 for a bit field
> + * should be defined using ``(1 << N)`` to be in line with other values such as
> + * ``(2 << N)`` for the same field.
>   *
>   * Group the register and its contents together without blank lines, separate
>   * from other registers and their contents with one blank line.
> @@ -105,7 +106,7 @@
>   *  #define _FOO_A                      0xf000
>   *  #define _FOO_B                      0xf001
>   *  #define FOO(pipe)                   _MMIO_PIPE(pipe, _FOO_A, _FOO_B)
> - *  #define   FOO_ENABLE                (1 << 31)
> + *  #define   FOO_ENABLE                BIT(31)

Oh! I'm sure that I will miss the (1 << n) notation...
and right now we had just converted everything to the documented style...

any chance of get a script modifying all at once?

Anyways:

Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

>   *  #define   FOO_MODE_MASK             (0xf << 16)
>   *  #define   FOO_MODE_SHIFT            16
>   *  #define   FOO_MODE_BAR              (0 << 16)
> -- 
> 2.11.0
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx