[PATCH v3 04/12] Revert "drm/udl: Kill pending URBs at suspend and disconnect"

Takashi Iwai
2022-09-08T09:51:35Z

This reverts the recent fix commit
e25d5954264d ("drm/udl: Kill pending URBs at suspend and disconnect")
as it turned out to lead to potential hangup at a disconnection, and
it doesn't help much for suspend/resume problem, either.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/udl/udl_drv.h | 2 --
drivers/gpu/drm/udl/udl_main.c | 25 +++----------------------
drivers/gpu/drm/udl/udl_modeset.c | 2 --
3 files changed, 3 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/udl/udl_drv.h b/drivers/gpu/drm/udl/udl_drv.h
index 37c14b0ff1fc..5923d2e02bc8 100644
--- a/drivers/gpu/drm/udl/udl_drv.h
+++ b/drivers/gpu/drm/udl/udl_drv.h
@@ -39,7 +39,6 @@ struct urb_node {

struct urb_list {
struct list_head list;
- struct list_head in_flight;
spinlock_t lock;
wait_queue_head_t sleep;
int available;
@@ -85,7 +84,6 @@ static inline struct urb *udl_get_urb(struct drm_device *dev)

int udl_submit_urb(struct drm_device *dev, struct urb *urb, size_t len);
int udl_sync_pending_urbs(struct drm_device *dev);
-void udl_kill_pending_urbs(struct drm_device *dev);
void udl_urb_completion(struct urb *urb);

int udl_init(struct udl_device *udl);
diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
index 7d1e6bbc165c..a9f6b710b254 100644
--- a/drivers/gpu/drm/udl/udl_main.c
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -135,7 +135,7 @@ void udl_urb_completion(struct urb *urb)
urb->transfer_buffer_length = udl->urbs.size; /* reset to actual */

spin_lock_irqsave(&udl->urbs.lock, flags);
- list_move(&unode->entry, &udl->urbs.list);
+ list_add_tail(&unode->entry, &udl->urbs.list);
udl->urbs.available++;
spin_unlock_irqrestore(&udl->urbs.lock, flags);

@@ -180,7 +180,6 @@ static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
retry:
udl->urbs.size = size;
INIT_LIST_HEAD(&udl->urbs.list);
- INIT_LIST_HEAD(&udl->urbs.in_flight);

init_waitqueue_head(&udl->urbs.sleep);
udl->urbs.count = 0;
@@ -247,7 +246,7 @@ struct urb *udl_get_urb_timeout(struct drm_device *dev, long timeout)
}

unode = list_first_entry(&udl->urbs.list, struct urb_node, entry);
- list_move(&unode->entry, &udl->urbs.in_flight);
+ list_del_init(&unode->entry);
udl->urbs.available--;

unlock:
@@ -281,7 +280,7 @@ int udl_sync_pending_urbs(struct drm_device *dev)
spin_lock_irq(&udl->urbs.lock);
/* 2 seconds as a sane timeout */
if (!wait_event_lock_irq_timeout(udl->urbs.sleep,
- list_empty(&udl->urbs.in_flight),
+ udl->urbs.available == udl->urbs.count,
udl->urbs.lock,
msecs_to_jiffies(2000)))
ret = -ETIMEDOUT;
@@ -289,23 +288,6 @@ int udl_sync_pending_urbs(struct drm_device *dev)
return ret;
}

-/* kill pending URBs */
-void udl_kill_pending_urbs(struct drm_device *dev)
-{
- struct udl_device *udl = to_udl(dev);
- struct urb_node *unode;
-
- spin_lock_irq(&udl->urbs.lock);
- while (!list_empty(&udl->urbs.in_flight)) {
- unode = list_first_entry(&udl->urbs.in_flight,
- struct urb_node, entry);
- spin_unlock_irq(&udl->urbs.lock);
- usb_kill_urb(unode->urb);
- spin_lock_irq(&udl->urbs.lock);
- }
- spin_unlock_irq(&udl->urbs.lock);
-}
-
int udl_init(struct udl_device *udl)
{
struct drm_device *dev = &udl->drm;
@@ -354,7 +336,6 @@ int udl_drop_usb(struct drm_device *dev)
{
struct udl_device *udl = to_udl(dev);

- udl_kill_pending_urbs(dev);
udl_free_urb_list(dev);
put_device(udl->dmadev);
udl->dmadev = NULL;
diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
index b2377b706482..cbdda2d8b882 100644
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -394,8 +394,6 @@ udl_simple_display_pipe_disable(struct drm_simple_display_pipe *pipe)
struct urb *urb;
char *buf;

- udl_kill_pending_urbs(dev);
-
urb = udl_get_urb(dev);
if (!urb)
return;
--
2.35.3