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
--- drivers/video/fbdev/udlfb.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-)
Index: linux-4.17-rc7/drivers/video/fbdev/udlfb.c =================================================================== --- linux-4.17-rc7.orig/drivers/video/fbdev/udlfb.c 2018-06-03 13:17:38.000000000 +0200 +++ linux-4.17-rc7/drivers/video/fbdev/udlfb.c 2018-06-03 13:17:38.000000000 +0200 @@ -1843,17 +1843,22 @@ static void dlfb_free_urb_list(struct dl
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 dl } 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 dl
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)