On Tue, Jan 26, 2021 at 05:58:12PM +0100, Gerd Hoffmann wrote:
> Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> ---
> drivers/gpu/drm/qxl/qxl_drv.h | 1 +
> drivers/gpu/drm/qxl/qxl_kms.c | 22 ++++++++++++++++++++--
> drivers/gpu/drm/qxl/qxl_release.c | 2 ++
> 3 files changed, 23 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/qxl/qxl_drv.h b/drivers/gpu/drm/qxl/qxl_drv.h
> index 01354b43c413..1c57b587b6a7 100644
> --- a/drivers/gpu/drm/qxl/qxl_drv.h
> +++ b/drivers/gpu/drm/qxl/qxl_drv.h
> @@ -214,6 +214,7 @@ struct qxl_device {
> spinlock_t release_lock;
> struct idr release_idr;
> uint32_t release_seqno;
> + atomic_t release_count;
> spinlock_t release_idr_lock;
> struct mutex async_io_mutex;
> unsigned int last_sent_io_cmd;
> diff --git a/drivers/gpu/drm/qxl/qxl_kms.c b/drivers/gpu/drm/qxl/qxl_kms.c
> index 4a60a52ab62e..f177f72bfc12 100644
> --- a/drivers/gpu/drm/qxl/qxl_kms.c
> +++ b/drivers/gpu/drm/qxl/qxl_kms.c
> @@ -25,6 +25,7 @@
>
> #include <linux/io-mapping.h>
> #include <linux/pci.h>
> +#include <linux/delay.h>
>
> #include <drm/drm_drv.h>
> #include <drm/drm_managed.h>
> @@ -286,8 +287,25 @@ int qxl_device_init(struct qxl_device *qdev,
>
> void qxl_device_fini(struct qxl_device *qdev)
> {
> - qxl_bo_unref(&qdev->current_release_bo[0]);
> - qxl_bo_unref(&qdev->current_release_bo[1]);
> + int cur_idx, try;
> +
> + for (cur_idx = 0; cur_idx < 3; cur_idx++) {
> + if (!qdev->current_release_bo[cur_idx])
> + continue;
> + qxl_bo_unpin(qdev->current_release_bo[cur_idx]);
> + qxl_bo_unref(&qdev->current_release_bo[cur_idx]);
> + qdev->current_release_bo_offset[cur_idx] = 0;
> + qdev->current_release_bo[cur_idx] = NULL;
> + }
> +
> + /*
> + * Ask host to release resources (+fill release ring),
> + * then wait for the release actually happening.
> + */
> + qxl_io_notify_oom(qdev);
> + for (try = 0; try < 20 && atomic_read(&qdev->release_count) > 0; try++)
> + msleep(20);
A bit icky, why not use a wait queue or something like that instead of
hand-rolling this? Not for perf reasons, just so it's a bit clear who
waits for whom and why.
-Daniel
> +
> qxl_gem_fini(qdev);
> qxl_bo_fini(qdev);
> flush_work(&qdev->gc_work);
> diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c
> index 28013fd1f8ea..43a5436853b7 100644
> --- a/drivers/gpu/drm/qxl/qxl_release.c
> +++ b/drivers/gpu/drm/qxl/qxl_release.c
> @@ -196,6 +196,7 @@ qxl_release_free(struct qxl_device *qdev,
> qxl_release_free_list(release);
> kfree(release);
> }
> + atomic_dec(&qdev->release_count);
> }
>
> static int qxl_release_bo_alloc(struct qxl_device *qdev,
> @@ -344,6 +345,7 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
> *rbo = NULL;
> return idr_ret;
> }
> + atomic_inc(&qdev->release_count);
>
> mutex_lock(&qdev->release_mutex);
> if (qdev->current_release_bo_offset[cur_idx] + 1 >= releases_per_bo[cur_idx]) {
> --
> 2.29.2
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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