3.16.62-rc1 review patch. If anyone has any objections, please let me know.
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From: Mikulas Patocka mpatocka@redhat.com
commit 080fb5240bdcabed7387b814139c3ea172d59fc5 upstream.
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 Signed-off-by: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com [bwh: Backported to 3.16: - Pointers to struct dlfb_data are named "dev" rather than "dlfb" - Adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/video/fbdev/udlfb.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-)
--- a/drivers/video/fbdev/udlfb.c +++ b/drivers/video/fbdev/udlfb.c @@ -1851,17 +1851,22 @@ static void dlfb_free_urb_list(struct dl
static int dlfb_alloc_urb_list(struct dlfb_data *dev, 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(&dev->urbs.lock);
+retry: dev->urbs.size = size; INIT_LIST_HEAD(&dev->urbs.list);
- while (i < count) { + sema_init(&dev->urbs.limit_sem, 0); + dev->urbs.count = 0; + dev->urbs.available = 0; + + while (dev->urbs.count * size < wanted_size) { unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL); if (!unode) break; @@ -1874,11 +1879,16 @@ static int dlfb_alloc_urb_list(struct dl } unode->urb = urb;
- buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL, + buf = usb_alloc_coherent(dev->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(dev); + goto retry; + } break; }
@@ -1889,14 +1899,12 @@ static int dlfb_alloc_urb_list(struct dl
list_add_tail(&unode->entry, &dev->urbs.list);
- i++; + up(&dev->urbs.limit_sem); + dev->urbs.count++; + dev->urbs.available++; }
- sema_init(&dev->urbs.limit_sem, i); - dev->urbs.count = i; - dev->urbs.available = i; - - return i; + return dev->urbs.count; }
static struct urb *dlfb_get_urb(struct dlfb_data *dev)