udlfb: fix hcd_buffer_free panic on unplug/replug
Fix race conditions with unplug/replug behavior, in particular take care not to hold up USB probe/disconnect for long-running framebuffer operations and rely on usb to handle teardown. Fix for kernel panic reported with new F17 multiseat support. Reported-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Bernie Thompson <bernie@plugable.com>
This commit is contained in:
Bernie Thompson
Родитель
9daee73c81
Коммит
8d21547d3c
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@ -918,10 +918,6 @@ static void dlfb_free(struct kref *kref)
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{
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struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
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/* this function will wait for all in-flight urbs to complete */
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if (dev->urbs.count > 0)
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dlfb_free_urb_list(dev);
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if (dev->backing_buffer)
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vfree(dev->backing_buffer);
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@ -940,35 +936,42 @@ static void dlfb_release_urb_work(struct work_struct *work)
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up(&unode->dev->urbs.limit_sem);
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}
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static void dlfb_free_framebuffer_work(struct work_struct *work)
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static void dlfb_free_framebuffer(struct dlfb_data *dev)
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{
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struct dlfb_data *dev = container_of(work, struct dlfb_data,
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free_framebuffer_work.work);
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struct fb_info *info = dev->info;
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int node = info->node;
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unregister_framebuffer(info);
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if (info) {
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int node = info->node;
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if (info->cmap.len != 0)
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fb_dealloc_cmap(&info->cmap);
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if (info->monspecs.modedb)
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fb_destroy_modedb(info->monspecs.modedb);
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if (info->screen_base)
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vfree(info->screen_base);
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unregister_framebuffer(info);
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fb_destroy_modelist(&info->modelist);
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if (info->cmap.len != 0)
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fb_dealloc_cmap(&info->cmap);
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if (info->monspecs.modedb)
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fb_destroy_modedb(info->monspecs.modedb);
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if (info->screen_base)
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vfree(info->screen_base);
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dev->info = 0;
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fb_destroy_modelist(&info->modelist);
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/* Assume info structure is freed after this point */
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framebuffer_release(info);
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dev->info = NULL;
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pr_warn("fb_info for /dev/fb%d has been freed\n", node);
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/* Assume info structure is freed after this point */
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framebuffer_release(info);
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pr_warn("fb_info for /dev/fb%d has been freed\n", node);
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}
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/* ref taken in probe() as part of registering framebfufer */
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kref_put(&dev->kref, dlfb_free);
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}
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static void dlfb_free_framebuffer_work(struct work_struct *work)
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{
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struct dlfb_data *dev = container_of(work, struct dlfb_data,
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free_framebuffer_work.work);
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dlfb_free_framebuffer(dev);
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}
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/*
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* Assumes caller is holding info->lock mutex (for open and release at least)
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*/
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@ -1571,14 +1574,15 @@ success:
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kfree(buf);
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return true;
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}
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static void dlfb_init_framebuffer_work(struct work_struct *work);
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static int dlfb_usb_probe(struct usb_interface *interface,
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const struct usb_device_id *id)
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{
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struct usb_device *usbdev;
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struct dlfb_data *dev = 0;
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struct fb_info *info = 0;
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int retval = -ENOMEM;
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int i;
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/* usb initialization */
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@ -1590,9 +1594,7 @@ static int dlfb_usb_probe(struct usb_interface *interface,
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goto error;
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}
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/* we need to wait for both usb and fbdev to spin down on disconnect */
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kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
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kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
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dev->udev = usbdev;
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dev->gdev = &usbdev->dev; /* our generic struct device * */
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@ -1620,10 +1622,39 @@ static int dlfb_usb_probe(struct usb_interface *interface,
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goto error;
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}
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kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
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/* We don't register a new USB class. Our client interface is fbdev */
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/* Workitem keep things fast & simple during USB enumeration */
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INIT_DELAYED_WORK(&dev->init_framebuffer_work,
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dlfb_init_framebuffer_work);
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schedule_delayed_work(&dev->init_framebuffer_work, 0);
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return 0;
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error:
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if (dev) {
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kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
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kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
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/* dev has been deallocated. Do not dereference */
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}
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return retval;
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}
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static void dlfb_init_framebuffer_work(struct work_struct *work)
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{
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struct dlfb_data *dev = container_of(work, struct dlfb_data,
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init_framebuffer_work.work);
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struct fb_info *info;
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int retval;
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int i;
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/* allocates framebuffer driver structure, not framebuffer memory */
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info = framebuffer_alloc(0, &interface->dev);
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info = framebuffer_alloc(0, dev->gdev);
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if (!info) {
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retval = -ENOMEM;
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pr_err("framebuffer_alloc failed\n");
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@ -1669,15 +1700,13 @@ static int dlfb_usb_probe(struct usb_interface *interface,
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for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) {
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retval = device_create_file(info->dev, &fb_device_attrs[i]);
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if (retval) {
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pr_err("device_create_file failed %d\n", retval);
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goto err_del_attrs;
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pr_warn("device_create_file failed %d\n", retval);
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}
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}
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retval = device_create_bin_file(info->dev, &edid_attr);
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if (retval) {
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pr_err("device_create_bin_file failed %d\n", retval);
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goto err_del_attrs;
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pr_warn("device_create_bin_file failed %d\n", retval);
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}
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pr_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
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@ -1685,38 +1714,10 @@ static int dlfb_usb_probe(struct usb_interface *interface,
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info->var.xres, info->var.yres,
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((dev->backing_buffer) ?
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info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
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return 0;
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err_del_attrs:
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for (i -= 1; i >= 0; i--)
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device_remove_file(info->dev, &fb_device_attrs[i]);
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return;
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error:
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if (dev) {
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if (info) {
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if (info->cmap.len != 0)
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fb_dealloc_cmap(&info->cmap);
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if (info->monspecs.modedb)
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fb_destroy_modedb(info->monspecs.modedb);
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if (info->screen_base)
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vfree(info->screen_base);
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fb_destroy_modelist(&info->modelist);
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framebuffer_release(info);
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}
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if (dev->backing_buffer)
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vfree(dev->backing_buffer);
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kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
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kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
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/* dev has been deallocated. Do not dereference */
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}
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return retval;
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dlfb_free_framebuffer(dev);
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}
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static void dlfb_usb_disconnect(struct usb_interface *interface)
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@ -1736,12 +1737,24 @@ static void dlfb_usb_disconnect(struct usb_interface *interface)
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/* When non-active we'll update virtual framebuffer, but no new urbs */
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atomic_set(&dev->usb_active, 0);
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/* remove udlfb's sysfs interfaces */
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for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
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device_remove_file(info->dev, &fb_device_attrs[i]);
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device_remove_bin_file(info->dev, &edid_attr);
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unlink_framebuffer(info);
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/* this function will wait for all in-flight urbs to complete */
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dlfb_free_urb_list(dev);
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if (info) {
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/* remove udlfb's sysfs interfaces */
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for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
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device_remove_file(info->dev, &fb_device_attrs[i]);
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device_remove_bin_file(info->dev, &edid_attr);
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/* it's safe to uncomment next line if your kernel
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doesn't yet have this function exported */
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unlink_framebuffer(info);
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}
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usb_set_intfdata(interface, NULL);
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dev->udev = NULL;
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dev->gdev = NULL;
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/* if clients still have us open, will be freed on last close */
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if (dev->fb_count == 0)
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@ -1807,12 +1820,12 @@ static void dlfb_free_urb_list(struct dlfb_data *dev)
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int ret;
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unsigned long flags;
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pr_notice("Waiting for completes and freeing all render urbs\n");
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pr_notice("Freeing all render urbs\n");
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/* keep waiting and freeing, until we've got 'em all */
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while (count--) {
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/* Getting interrupted means a leak, but ok at shutdown*/
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/* Getting interrupted means a leak, but ok at disconnect */
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ret = down_interruptible(&dev->urbs.limit_sem);
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if (ret)
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break;
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@ -1834,6 +1847,7 @@ static void dlfb_free_urb_list(struct dlfb_data *dev)
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kfree(node);
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}
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dev->urbs.count = 0;
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}
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static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
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@ -41,6 +41,7 @@ struct dlfb_data {
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char *backing_buffer;
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int fb_count;
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bool virtualized; /* true when physical usb device not present */
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struct delayed_work init_framebuffer_work;
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struct delayed_work free_framebuffer_work;
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atomic_t usb_active; /* 0 = update virtual buffer, but no usb traffic */
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atomic_t lost_pixels; /* 1 = a render op failed. Need screen refresh */
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