Commit 080fb524 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Bartlomiej Zolnierkiewicz
Browse files

udlfb: handle allocation failure 



Allocations larger than PAGE_ALLOC_COSTLY_ORDER are unreliable and they
may fail anytime. This patch fixes the udlfb driver so that when a large
alloactions fails, it tries to do multiple smaller allocations.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
parent bb24153a

drivers/video/fbdev/udlfb.c

+17 −9
Original line number Diff line number Diff line
@@ -1843,17 +1843,22 @@ static void dlfb_free_urb_list(struct dlfb_data *dlfb) 


static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size)

{

	int i = 0;

	struct urb *urb;

	struct urb_node *unode;

	char *buf;

	size_t wanted_size = count * size;



	spin_lock_init(&dlfb->urbs.lock);



retry:

	dlfb->urbs.size = size;

	INIT_LIST_HEAD(&dlfb->urbs.list);



	while (i < count) {

	sema_init(&dlfb->urbs.limit_sem, 0);

	dlfb->urbs.count = 0;

	dlfb->urbs.available = 0;



	while (dlfb->urbs.count * size < wanted_size) {

		unode = kzalloc(sizeof(*unode), GFP_KERNEL);

		if (!unode)

			break;
@@ -1866,11 +1871,16 @@ static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size) 
		}

		unode->urb = urb;



		buf = usb_alloc_coherent(dlfb->udev, MAX_TRANSFER, GFP_KERNEL,

		buf = usb_alloc_coherent(dlfb->udev, size, GFP_KERNEL,

					 &urb->transfer_dma);

		if (!buf) {

			kfree(unode);

			usb_free_urb(urb);

			if (size > PAGE_SIZE) {

				size /= 2;

				dlfb_free_urb_list(dlfb);

				goto retry;

			}

			break;

		}
@@ -1881,14 +1891,12 @@ static int dlfb_alloc_urb_list(struct dlfb_data *dlfb, int count, size_t size) 


		list_add_tail(&unode->entry, &dlfb->urbs.list);



		i++;

		up(&dlfb->urbs.limit_sem);

		dlfb->urbs.count++;

		dlfb->urbs.available++;

	}



	sema_init(&dlfb->urbs.limit_sem, i);

	dlfb->urbs.count = i;

	dlfb->urbs.available = i;



	return i;

	return dlfb->urbs.count;

}



static struct urb *dlfb_get_urb(struct dlfb_data *dlfb)

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