From 080fb5240bdcabed7387b814139c3ea172d59fc5 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 25 Jul 2018 15:41:56 +0200 Subject: [PATCH] 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 Cc: stable@vger.kernel.org Signed-off-by: Bartlomiej Zolnierkiewicz --- drivers/video/fbdev/udlfb.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c index 770c1c8cfbd0..4ab903456129 100644 --- a/drivers/video/fbdev/udlfb.c +++ b/drivers/video/fbdev/udlfb.c @@ -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)