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: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
This commit is contained in:
Mikulas Patocka 2018-07-25 15:41:56 +02:00 committed by Bartlomiej Zolnierkiewicz
parent bb24153a3f
commit 080fb5240b
1 changed files with 17 additions and 9 deletions

View File

@ -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)