Re: [PATCH 2/4] drm/radeon: Remove unused radeon_doorbell_free

["Dr. David Alan Gilbert" <linux@treblig.org>]

* Alex Deucher (alexdeucher@gmail.com) wrote:
> On Sun, May 11, 2025 at 8:13 AM Dr. David Alan Gilbert
> <linux@treblig.org> wrote:
> >
> > * Christophe JAILLET (christophe.jaillet@wanadoo.fr) wrote:
> > > Le 18/04/2025 à 02:21, linux@treblig.org a écrit :
> > > > From: "Dr. David Alan Gilbert" <linux@treblig.org>
> > > >
> > > > radeon_doorbell_free() was added in 2013 by
> > > > commit 75efdee11b5d ("drm/radeon: implement simple doorbell page
> > > > allocator")
> > > > but never used.
> > >
> > > Hi,
> > >
> > > I think than instead of being removed, it should be used in the error
> > > handling path of cik_init() and in cik_fini().
> >
> > OK, here's an RFC that builds; but if I understand correctly only
> > some devices run this code, and I'm not sure mine does;
> >
> > Thoughts?
> >
> > Dave
> >
> > From 15b3830b4ee3eb819f86198dcbc596428f9ee0d0 Mon Sep 17 00:00:00 2001
> > From: "Dr. David Alan Gilbert" <linux@treblig.org>
> > Date: Sun, 11 May 2025 02:35:41 +0100
> > Subject: [RFC PATCH] drm/radeon/cik: Clean up doorbells
> >
> > Free doorbells in the error paths of cik_init and in cik_fini.
> >
> > Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> > Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
> > ---
> >  drivers/gpu/drm/radeon/cik.c | 38 ++++++++++++++++++++++++------------
> >  1 file changed, 26 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c
> > index 11a492f21157..3caa5a100f97 100644
> > --- a/drivers/gpu/drm/radeon/cik.c
> > +++ b/drivers/gpu/drm/radeon/cik.c
> > @@ -8548,7 +8548,7 @@ int cik_suspend(struct radeon_device *rdev)
> >   */
> >  int cik_init(struct radeon_device *rdev)
> >  {
> > -       struct radeon_ring *ring;
> > +       struct radeon_ring *ring, *ringCP1, *ringCP2;
> 
> I'd prefer ring_cp1 and ring_cp2 for readability.

OK.

> >         int r;
> >
> >         /* Read BIOS */
> > @@ -8623,19 +8623,22 @@ int cik_init(struct radeon_device *rdev)
> >         ring->ring_obj = NULL;
> >         r600_ring_init(rdev, ring, 1024 * 1024);
> >
> > -       ring = &rdev->ring[CAYMAN_RING_TYPE_CP1_INDEX];
> > -       ring->ring_obj = NULL;
> > -       r600_ring_init(rdev, ring, 1024 * 1024);
> > -       r = radeon_doorbell_get(rdev, &ring->doorbell_index);
> > +       ringCP1 = &rdev->ring[CAYMAN_RING_TYPE_CP1_INDEX];
> > +       ringCP2 = &rdev->ring[CAYMAN_RING_TYPE_CP2_INDEX];
> > +       ringCP1->ring_obj = NULL;
> > +       ringCP2->ring_obj = NULL;
> > +       ringCP1->doorbell_index = RADEON_MAX_DOORBELLS;
> > +       ringCP2->doorbell_index = RADEON_MAX_DOORBELLS;
> > +
> > +       r600_ring_init(rdev, ringCP1, 1024 * 1024);
> > +       r = radeon_doorbell_get(rdev, &ringCP1->doorbell_index);
> >         if (r)
> >                 return r;
> >
> > -       ring = &rdev->ring[CAYMAN_RING_TYPE_CP2_INDEX];
> > -       ring->ring_obj = NULL;
> > -       r600_ring_init(rdev, ring, 1024 * 1024);
> > -       r = radeon_doorbell_get(rdev, &ring->doorbell_index);
> > +       r600_ring_init(rdev, ringCP2, 1024 * 1024);
> > +       r = radeon_doorbell_get(rdev, &ringCP2->doorbell_index);
> >         if (r)
> > -               return r;
> > +               goto out;
> >
> >         ring = &rdev->ring[R600_RING_TYPE_DMA_INDEX];
> >         ring->ring_obj = NULL;
> > @@ -8653,7 +8656,7 @@ int cik_init(struct radeon_device *rdev)
> >
> >         r = r600_pcie_gart_init(rdev);
> >         if (r)
> > -               return r;
> > +               goto out;
> >
> >         rdev->accel_working = true;
> >         r = cik_startup(rdev);
> 
> I think you can drop the doorbells in the error case for cik_startup()
> as well since they won't be used in that case.

OK, can do that.

Thanks,

Dave

> Alex
> 
> > @@ -8678,10 +8681,16 @@ int cik_init(struct radeon_device *rdev)
> >          */
> >         if (!rdev->mc_fw && !(rdev->flags & RADEON_IS_IGP)) {
> >                 DRM_ERROR("radeon: MC ucode required for NI+.\n");
> > -               return -EINVAL;
> > +               r = -EINVAL;
> > +               goto out;
> >         }
> >
> >         return 0;
> > +
> > +out:
> > +       radeon_doorbell_free(rdev, ringCP1->doorbell_index);
> > +       radeon_doorbell_free(rdev, ringCP2->doorbell_index);
> > +       return r;
> >  }
> >
> >  /**
> > @@ -8695,6 +8704,7 @@ int cik_init(struct radeon_device *rdev)
> >   */
> >  void cik_fini(struct radeon_device *rdev)
> >  {
> > +       struct radeon_ring *ring;
> >         radeon_pm_fini(rdev);
> >         cik_cp_fini(rdev);
> >         cik_sdma_fini(rdev);
> > @@ -8708,6 +8718,10 @@ void cik_fini(struct radeon_device *rdev)
> >         radeon_ib_pool_fini(rdev);
> >         radeon_irq_kms_fini(rdev);
> >         uvd_v1_0_fini(rdev);
> > +       ring = &rdev->ring[CAYMAN_RING_TYPE_CP1_INDEX];
> > +       radeon_doorbell_free(rdev, ring->doorbell_index);
> > +       ring = &rdev->ring[CAYMAN_RING_TYPE_CP2_INDEX];
> > +       radeon_doorbell_free(rdev, ring->doorbell_index);
> >         radeon_uvd_fini(rdev);
> >         radeon_vce_fini(rdev);
> >         cik_pcie_gart_fini(rdev);
> > --
> > 2.49.0
> >
> >
> > --
> >  -----Open up your eyes, open up your mind, open up your code -------
> > / Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \
> > \        dave @ treblig.org |                               | In Hex /
> >  \ _________________________|_____ http://www.treblig.org   |_______/
-- 
 -----Open up your eyes, open up your mind, open up your code -------   
/ Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \ 
\        dave @ treblig.org |                               | In Hex /
 \ _________________________|_____ http://www.treblig.org   |_______/