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

[Alex Deucher]

On Sun, May 11, 2025 at 8:13 AM Dr. David Alan Gilbert
<linux at treblig.org> wrote:
>
> * Christophe JAILLET (christophe.jaillet at wanadoo.fr) wrote:
> > Le 18/04/2025 à 02:21, linux at treblig.org a écrit :
> > > From: "Dr. David Alan Gilbert" <linux at 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 at 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 at wanadoo.fr>
> Signed-off-by: Dr. David Alan Gilbert <linux at 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.

>         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.

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   |_______/