Re: [Intel-gfx] [PATCH v6 22/57] drm_print: condense enum drm_debug_category

Daniel Vetter
2022-09-07T06:09:58Z

On Sun, Sep 04, 2022 at 03:40:59PM -0600, Jim Cromie wrote:
> enum drm_debug_category has 10 categories, but is initialized with
> bitmasks which require 10 bits of underlying storage. By using
> natural enumeration, and moving the BIT(cat) into drm_debug_enabled(),
> the enum fits in 4 bits, allowing the category to be represented
> directly in pr_debug callsites, via the ddebug.class_id field.
>
> While this slightly pessimizes the bit-test in drm_debug_enabled(),
> using dyndbg with JUMP_LABEL will avoid the function entirely.
>
> NOTE: this change forecloses the possibility of doing:
>
> drm_dbg(DRM_UT_CORE|DRM_UT_KMS, "weird 2-cat experiment")
>
> but thats already strongly implied by the use of the enum itself; its
> not a normal enum if it can be 2 values simultaneously.
>
> Signed-off-by: Jim Cromie <jim.cromie@gmail.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

I guess this would also be a good patch to apply already, so we reduce the
patch set size somewhat?
-Daniel

> ---
> include/drm/drm_print.h | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
> index 22fabdeed297..b3b470440e46 100644
> --- a/include/drm/drm_print.h
> +++ b/include/drm/drm_print.h
> @@ -279,49 +279,49 @@ enum drm_debug_category {
> * @DRM_UT_CORE: Used in the generic drm code: drm_ioctl.c, drm_mm.c,
> * drm_memory.c, ...
> */
> - DRM_UT_CORE = 0x01,
> + DRM_UT_CORE,
> /**
> * @DRM_UT_DRIVER: Used in the vendor specific part of the driver: i915,
> * radeon, ... macro.
> */
> - DRM_UT_DRIVER = 0x02,
> + DRM_UT_DRIVER,
> /**
> * @DRM_UT_KMS: Used in the modesetting code.
> */
> - DRM_UT_KMS = 0x04,
> + DRM_UT_KMS,
> /**
> * @DRM_UT_PRIME: Used in the prime code.
> */
> - DRM_UT_PRIME = 0x08,
> + DRM_UT_PRIME,
> /**
> * @DRM_UT_ATOMIC: Used in the atomic code.
> */
> - DRM_UT_ATOMIC = 0x10,
> + DRM_UT_ATOMIC,
> /**
> * @DRM_UT_VBL: Used for verbose debug message in the vblank code.
> */
> - DRM_UT_VBL = 0x20,
> + DRM_UT_VBL,
> /**
> * @DRM_UT_STATE: Used for verbose atomic state debugging.
> */
> - DRM_UT_STATE = 0x40,
> + DRM_UT_STATE,
> /**
> * @DRM_UT_LEASE: Used in the lease code.
> */
> - DRM_UT_LEASE = 0x80,
> + DRM_UT_LEASE,
> /**
> * @DRM_UT_DP: Used in the DP code.
> */
> - DRM_UT_DP = 0x100,
> + DRM_UT_DP,
> /**
> * @DRM_UT_DRMRES: Used in the drm managed resources code.
> */
> - DRM_UT_DRMRES = 0x200,
> + DRM_UT_DRMRES
> };
>
> static inline bool drm_debug_enabled(enum drm_debug_category category)
> {
> - return unlikely(__drm_debug & category);
> + return unlikely(__drm_debug & BIT(category));
> }
>
> /*
> --
> 2.37.2
>

--
Daniel Vetter
Software Engineer, Intel Corporation