udl_alloc_urb_list() retires the allocation if there is no enough room
left, and it reinitializes the stuff unnecessarily such as the linked
list head and the waitqueue, which could be harmful.  Those should be
outside the retry loop.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/gpu/drm/udl/udl_main.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
index 19dc8317e843..c1f4b6199949 100644
--- a/drivers/gpu/drm/udl/udl_main.c
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -187,15 +187,14 @@ static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
 	struct usb_device *udev = udl_to_usb_device(udl);
 
 	spin_lock_init(&udl->urbs.lock);
-
-retry:
-	udl->urbs.size = size;
 	INIT_LIST_HEAD(&udl->urbs.list);
-
 	init_waitqueue_head(&udl->urbs.sleep);
 	udl->urbs.count = 0;
 	udl->urbs.available = 0;
 
+retry:
+	udl->urbs.size = size;
+
 	while (udl->urbs.count * size < wanted_size) {
 		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
 		if (!unode)
-- 
2.35.3

Am 16.08.22 um 17:36 schrieb Takashi Iwai:
> udl_alloc_urb_list() retires the allocation if there is no enough room
> left, and it reinitializes the stuff unnecessarily such as the linked
> list head and the waitqueue, which could be harmful.  Those should be
> outside the retry loop.
> 
> Signed-off-by: Takashi Iwai <tiwai@suse.de>

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>

> ---
>   drivers/gpu/drm/udl/udl_main.c | 7 +++----
>   1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
> index 19dc8317e843..c1f4b6199949 100644
> --- a/drivers/gpu/drm/udl/udl_main.c
> +++ b/drivers/gpu/drm/udl/udl_main.c
> @@ -187,15 +187,14 @@ static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
>   	struct usb_device *udev = udl_to_usb_device(udl);
>   
>   	spin_lock_init(&udl->urbs.lock);
> -
> -retry:
> -	udl->urbs.size = size;
>   	INIT_LIST_HEAD(&udl->urbs.list);
> -
>   	init_waitqueue_head(&udl->urbs.sleep);
>   	udl->urbs.count = 0;
>   	udl->urbs.available = 0;
>   
> +retry:
> +	udl->urbs.size = size;
> +
>   	while (udl->urbs.count * size < wanted_size) {
>   		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
>   		if (!unode)

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev