From 542bb9788a1f485eb1a2229178f665d8ea166156 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Sun, 3 Jun 2018 16:40:56 +0200 Subject: [PATCH] udl-kms: handle allocation failure Allocations larger than PAGE_ALLOC_COSTLY_ORDER are unreliable and they may fail anytime. This patch fixes the udl kms 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: Dave Airlie --- drivers/gpu/drm/udl/udl_main.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c index 1239decd46ff..7e9ad926926a 100644 --- a/drivers/gpu/drm/udl/udl_main.c +++ b/drivers/gpu/drm/udl/udl_main.c @@ -200,17 +200,22 @@ static void udl_free_urb_list(struct drm_device *dev) static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size) { struct udl_device *udl = dev->dev_private; - int i = 0; struct urb *urb; struct urb_node *unode; char *buf; + size_t wanted_size = count * size; spin_lock_init(&udl->urbs.lock); +retry: udl->urbs.size = size; INIT_LIST_HEAD(&udl->urbs.list); - while (i < count) { + sema_init(&udl->urbs.limit_sem, 0); + udl->urbs.count = 0; + udl->urbs.available = 0; + + while (udl->urbs.count * size < wanted_size) { unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL); if (!unode) break; @@ -226,11 +231,16 @@ static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size) } unode->urb = urb; - buf = usb_alloc_coherent(udl->udev, MAX_TRANSFER, GFP_KERNEL, + buf = usb_alloc_coherent(udl->udev, size, GFP_KERNEL, &urb->transfer_dma); if (!buf) { kfree(unode); usb_free_urb(urb); + if (size > PAGE_SIZE) { + size /= 2; + udl_free_urb_list(dev); + goto retry; + } break; } @@ -241,16 +251,14 @@ static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size) list_add_tail(&unode->entry, &udl->urbs.list); - i++; + up(&udl->urbs.limit_sem); + udl->urbs.count++; + udl->urbs.available++; } - sema_init(&udl->urbs.limit_sem, i); - udl->urbs.count = i; - udl->urbs.available = i; - - DRM_DEBUG("allocated %d %d byte urbs\n", i, (int) size); + DRM_DEBUG("allocated %d %d byte urbs\n", udl->urbs.count, (int) size); - return i; + return udl->urbs.count; } struct urb *udl_get_urb(struct drm_device *dev) -- 2.11.4.GIT