Re: [PATCH v9 30/52] drm-dyndbg: adapt drm core to use dyndbg classmaps-v2

jim.cromie
2024-07-03T02:35:06Z

On Tue, Jul 2, 2024 at 5:33 PM Ville Syrjälä
<ville.syrjala@linux.intel.com> wrote:
>
> On Tue, Jul 02, 2024 at 03:57:20PM -0600, Jim Cromie wrote:
> > dyndbg's CLASSMAP-v1 api was broken; DECLARE_DYNDBG_CLASSMAP tried to
> > do too much. Its replaced by DRM_CLASSMAP_DEFINE, which creates &
> > EXPORTs the classmap when CONFIG_DRM_USE_DYNAMIC_DEBUG=y, for direct
> > reference by drivers.
> >
> > The drivers still use DECLARE_DYNDBG_CLASSMAP for now, so they still
> > redundantly re-declare the classmap, but we can convert the drivers
> > later to DYNDBG_CLASSMAP_USE
> >
> > Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
> > ---
> > drivers/gpu/drm/drm_print.c | 25 +++++++++++++------------
> > include/drm/drm_print.h | 8 ++++++++
> > 2 files changed, 21 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
> > index 699b7dbffd7b..4a5f2317229b 100644
> > --- a/drivers/gpu/drm/drm_print.c
> > +++ b/drivers/gpu/drm/drm_print.c
> > @@ -55,18 +55,19 @@ MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug cat
> > #if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
> > module_param_named(debug, __drm_debug, ulong, 0600);
> > #else
> > -/* classnames must match vals of enum drm_debug_category */
> > -DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
> > - "DRM_UT_CORE",
> > - "DRM_UT_DRIVER",
> > - "DRM_UT_KMS",
> > - "DRM_UT_PRIME",
> > - "DRM_UT_ATOMIC",
> > - "DRM_UT_VBL",
> > - "DRM_UT_STATE",
> > - "DRM_UT_LEASE",
> > - "DRM_UT_DP",
> > - "DRM_UT_DRMRES");
> > +/* classnames must match value-symbols of enum drm_debug_category */
> > +DRM_CLASSMAP_DEFINE(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS,
> > + DRM_UT_CORE,
> > + "DRM_UT_CORE",
> > + "DRM_UT_DRIVER",
> > + "DRM_UT_KMS",
> > + "DRM_UT_PRIME",
> > + "DRM_UT_ATOMIC",
> > + "DRM_UT_VBL",
> > + "DRM_UT_STATE",
> > + "DRM_UT_LEASE",
> > + "DRM_UT_DP",
> > + "DRM_UT_DRMRES");
>
> Looks like this stuff just ends up in an array, so presumably
> it should be possible to use designated initializers to make this
> less fragile?

Im not sure I got your whole point, but:

the fragility is the repetitive re-statement of the map,
in those un-modified DECLARE_s,
once replaced, the USEs just ref the struct built by the _DEFINE
(once, and exported)

I dont really like the _DEFINEs restatement of the enum-values: DRM_UT_*
especially as "strings".
I can automate the stringification with an APPLY_FN_(__stringify, ...)
but the enum-list DRM_UT_* (w.o quotes) is still needed as args.

unless there is something C can do thats like Enum.values() ?

>
> --
> Ville Syrjälä
> Intel