[PATCH] fb: udlfb: fix scheduling while atomic.
From: Alexander Holler <hidden>
Date: 2013-01-05 11:42:54
Also in:
lkml, stable
Subsystem:
framebuffer layer, the rest · Maintainers:
Helge Deller, Linus Torvalds
The console functions are using spinlocks while calling fb-driver ops
but udlfb waits for a semaphore in many ops. This results in the BUG
"scheduling while atomic". One of those call flows is e.g.
vt_console_print() (spinlock printing_lock)
(...)
dlfb_ops_imageblit()
dlfb_handle_damage()
dlfb_get_urb()
down_timeout(semaphore)
BUG: scheduling while atomic
(...)
vt_console_print() (release spinlock printing_lock)
Fix this through a workqueue for dlfb_handle_damage().
Cc: <redacted>
Signed-off-by: Alexander Holler <redacted>
---
drivers/video/udlfb.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 51 insertions(+), 2 deletions(-)
diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c
index 86d449e..5aadcb2 100644
--- a/drivers/video/udlfb.c
+++ b/drivers/video/udlfb.c@@ -569,7 +569,7 @@ static int dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr, return 0; } -int dlfb_handle_damage(struct dlfb_data *dev, int x, int y, +int dlfb_handle_damage_queued(struct dlfb_data *dev, int x, int y, int width, int height, char *data) { int i, ret;
@@ -630,6 +630,44 @@ error: return 0; } +static struct workqueue_struct *dlfb_handle_damage_wq; + +struct dlfb_handle_damage_work { + struct work_struct my_work; + struct dlfb_data *dev; + char *data; + int x, y, width, height; +}; + +static void dlfb_handle_damage_work(struct work_struct *work) +{ + struct dlfb_handle_damage_work *my_work + (struct dlfb_handle_damage_work *)work; + + dlfb_handle_damage_queued(my_work->dev, my_work->x, my_work->y, + my_work->width, my_work->height, my_work->data); + kfree(work); + return; +} + +void dlfb_handle_damage(struct dlfb_data *dev, int x, int y, + int width, int height, char *data) +{ + struct dlfb_handle_damage_work *work + kmalloc(sizeof(struct dlfb_handle_damage_work), GFP_KERNEL); + + if (work) { + INIT_WORK((struct work_struct *)work, dlfb_handle_damage_work); + work->dev = dev; + work->x = x; + work->y = y; + work->width = width; + work->height = height; + work->data = data; + queue_work(dlfb_handle_damage_wq, (struct work_struct *)work); + } +} + /* * Path triggered by usermode clients who write to filesystem * e.g. cat filename > /dev/fb1
@@ -945,6 +983,9 @@ static void dlfb_free_framebuffer(struct dlfb_data *dev) unregister_framebuffer(info); + if (dlfb_handle_damage_wq) + destroy_workqueue(dlfb_handle_damage_wq); + if (info->cmap.len != 0) fb_dealloc_cmap(&info->cmap); if (info->monspecs.modedb)
@@ -1626,13 +1667,13 @@ static int dlfb_usb_probe(struct usb_interface *interface, dev->sku_pixel_limit = pixel_limit; } - if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) { retval = -ENOMEM; pr_err("dlfb_alloc_urb_list failed\n"); goto error; } + kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */ /* We don't register a new USB class. Our client interface is fbdev */
@@ -1694,6 +1735,13 @@ static void dlfb_init_framebuffer_work(struct work_struct *work) goto error; } + dlfb_handle_damage_wq = alloc_workqueue("udlfb_damage", + WQ_MEM_RECLAIM, 0); + if (dlfb_handle_damage_wq = NULL) { + pr_err("unable to allocate workqueue\n"); + goto error; + } + /* ready to begin using device */ atomic_set(&dev->usb_active, 1);
@@ -1702,6 +1750,7 @@ static void dlfb_init_framebuffer_work(struct work_struct *work) dlfb_ops_check_var(&info->var, info); dlfb_ops_set_par(info); + retval = register_framebuffer(info); if (retval < 0) { pr_err("register_framebuffer failed %d\n", retval);
--
1.7.11.7