Re: [PATCH v2] drm/vc4: replace idr_init() by idr_init_base()

Maxime Ripard
2020-11-06T10:52:55Z

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On Thu, Nov 05, 2020 at 01:24:14PM -0800, Eric Anholt wrote:
> On Thu, Nov 5, 2020 at 12:21 PM Deepak R Varma <mh12gx2825@gmail.com> wrote:
> >
> > idr_init() uses base 0 which is an invalid identifier for this driver.
> > The idr_alloc for this driver uses VC4_PERFMONID_MIN as start value for
> > ID range and it is #defined to 1. The new function idr_init_base allows
> > IDR to set the ID lookup from base 1. This avoids all lookups that
> > otherwise starts from 0 since 0 is always unused / available.
> >
> > References: commit 6ce711f27500 ("idr: Make 1-based IDRs more efficient")
> >
> > Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
> > ---
> > Changes since v1:
> > - Change suggested by Eric Anholt
> > 1. Use VC4_PERFMONID_MIN instead of magic number 1
> >
> > drivers/gpu/drm/vc4/vc4_perfmon.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/vc4/vc4_perfmon.c b/drivers/gpu/drm/vc4/vc4_perfmon.c
> > index f4aa75efd16b..18abc06335c1 100644
> > --- a/drivers/gpu/drm/vc4/vc4_perfmon.c
> > +++ b/drivers/gpu/drm/vc4/vc4_perfmon.c
> > @@ -77,7 +77,7 @@ struct vc4_perfmon *vc4_perfmon_find(struct vc4_file *vc4file, int id)
> > void vc4_perfmon_open_file(struct vc4_file *vc4file)
> > {
> > mutex_init(&vc4file->perfmon.lock);
> > - idr_init(&vc4file->perfmon.idr);
> > + idr_init_base(&vc4file->perfmon.idr, VC4_PERFMONID_MIN);
> > }
> >
> > static int vc4_perfmon_idr_del(int id, void *elem, void *data)
> > --
> > 2.25.1
>
> Reviewed-by: Eric Anholt <eric@anholt.net>
>
> hopefully Maxime can apply it.

Applied, thanks!
Maxime

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