2020-04-17 19:45:11

by Lyude Paul

Subject: [RFC v3 01/11] drm/vblank: Register drmm cleanup action once per drm_vblank_crtc

Since we'll be allocating resources for kthread_create_worker() in the
next commit (which could fail and require us to clean up the mess),
let's simplify the cleanup process a bit by registering a
drm_vblank_init_release() action for each drm_vblank_crtc so they're
still cleaned up if we fail to initialize one of them.

Signed-off-by: Lyude Paul <[email protected]>
---
drivers/gpu/drm/drm_vblank.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 758bf74e1cab..bf8de10c131f 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -491,16 +491,12 @@ static void vblank_disable_fn(struct timer_list *t)

static void drm_vblank_init_release(struct drm_device *dev, void *ptr)
{
- unsigned int pipe;
-
- for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
- struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ struct drm_vblank_crtc *vblank = ptr;

- WARN_ON(READ_ONCE(vblank->enabled) &&
- drm_core_check_feature(dev, DRIVER_MODESET));
+ WARN_ON(READ_ONCE(vblank->enabled) &&
+ drm_core_check_feature(dev, DRIVER_MODESET));

- del_timer_sync(&vblank->disable_timer);
- }
+ del_timer_sync(&vblank->disable_timer);
}

/**
@@ -529,10 +525,6 @@ int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)

dev->num_crtcs = num_crtcs;

- ret = drmm_add_action(dev, drm_vblank_init_release, NULL);
- if (ret)
- return ret;
-
for (i = 0; i < num_crtcs; i++) {
struct drm_vblank_crtc *vblank = &dev->vblank[i];

@@ -541,6 +533,12 @@ int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
init_waitqueue_head(&vblank->queue);
timer_setup(&vblank->disable_timer, vblank_disable_fn, 0);
seqlock_init(&vblank->seqlock);
+
+ ret = drmm_add_action(dev, drm_vblank_init_release, vblank);
+ if (ret) {
+ del_timer_sync(&vblank->disable_timer);
+ return ret;
+ }
}

DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
--
2.25.1

2020-04-21 12:31:42

by Daniel Vetter

Subject: Re: [RFC v3 01/11] drm/vblank: Register drmm cleanup action once per drm_vblank_crtc

On Fri, Apr 17, 2020 at 03:40:48PM -0400, Lyude Paul wrote:
> Since we'll be allocating resources for kthread_create_worker() in the
> next commit (which could fail and require us to clean up the mess),
> let's simplify the cleanup process a bit by registering a
> drm_vblank_init_release() action for each drm_vblank_crtc so they're
> still cleaned up if we fail to initialize one of them.
>
> Signed-off-by: Lyude Paul <[email protected]>
> ---
> drivers/gpu/drm/drm_vblank.c | 22 ++++++++++------------
> 1 file changed, 10 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> index 758bf74e1cab..bf8de10c131f 100644
> --- a/drivers/gpu/drm/drm_vblank.c
> +++ b/drivers/gpu/drm/drm_vblank.c
> @@ -491,16 +491,12 @@ static void vblank_disable_fn(struct timer_list *t)
>
> static void drm_vblank_init_release(struct drm_device *dev, void *ptr)
> {
> - unsigned int pipe;
> -
> - for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
> - struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
> + struct drm_vblank_crtc *vblank = ptr;
>
> - WARN_ON(READ_ONCE(vblank->enabled) &&
> - drm_core_check_feature(dev, DRIVER_MODESET));
> + WARN_ON(READ_ONCE(vblank->enabled) &&
> + drm_core_check_feature(dev, DRIVER_MODESET));
>
> - del_timer_sync(&vblank->disable_timer);
> - }
> + del_timer_sync(&vblank->disable_timer);
> }
>
> /**
> @@ -529,10 +525,6 @@ int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
>
> dev->num_crtcs = num_crtcs;
>
> - ret = drmm_add_action(dev, drm_vblank_init_release, NULL);
> - if (ret)
> - return ret;
> -
> for (i = 0; i < num_crtcs; i++) {
> struct drm_vblank_crtc *vblank = &dev->vblank[i];
>
> @@ -541,6 +533,12 @@ int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
> init_waitqueue_head(&vblank->queue);
> timer_setup(&vblank->disable_timer, vblank_disable_fn, 0);
> seqlock_init(&vblank->seqlock);
> +
> + ret = drmm_add_action(dev, drm_vblank_init_release, vblank);

drmm_add_action_or_reset probably what you want. I've gone so far an
unexport the plain variant.
-Daniel

> + if (ret) {
> + del_timer_sync(&vblank->disable_timer);
> + return ret;
> + }
> }
>
> DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
> --
> 2.25.1
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch