From 6ee80c0330b0413b9daa9e2aa9142554de290bdc Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Sat, 28 Jan 2012 19:57:46 +0000 Subject: [PATCH] udlfb: remove sysfs framebuffer device with USB .disconnect() commit ce880cb860f36694d2cdebfac9e6ae18176fe4c4 upstream. The USB graphics card driver delays the unregistering of the framebuffer device to a workqueue, which breaks the userspace visible remove uevent sequence. Recent userspace tools started to support USB graphics card hotplug out-of-the-box and rely on proper events sent by the kernel. The framebuffer device is a direct child of the USB interface which is removed immediately after the USB .disconnect() callback. But the fb device in /sys stays around until its final cleanup, at a time where all the parent devices have been removed already. To work around that, we remove the sysfs fb device directly in the USB .disconnect() callback and leave only the cleanup of the internal fb data to the delayed work. Before: add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2 (usb) add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0 (usb) add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/graphics/fb0 (graphics) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0 (usb) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2 (usb) remove /2-1.2:1.0/graphics/fb0 (graphics) After: add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2 (usb) add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0 (usb) add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/graphics/fb1 (graphics) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/graphics/fb1 (graphics) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0 (usb) remove /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2 (usb) Tested-by: Bernie Thompson Acked-by: Bernie Thompson Signed-off-by: Kay Sievers Signed-off-by: Florian Tobias Schandinat Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbmem.c | 18 +++++++++++++++++- drivers/video/udlfb.c | 2 +- include/linux/fb.h | 1 + 3 files changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c index ad936295d8f4..7a41220aebdd 100644 --- a/drivers/video/fbmem.c +++ b/drivers/video/fbmem.c @@ -1651,6 +1651,7 @@ static int do_unregister_framebuffer(struct fb_info *fb_info) if (ret) return -EINVAL; + unlink_framebuffer(fb_info); if (fb_info->pixmap.addr && (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT)) kfree(fb_info->pixmap.addr); @@ -1658,7 +1659,6 @@ static int do_unregister_framebuffer(struct fb_info *fb_info) registered_fb[i] = NULL; num_registered_fb--; fb_cleanup_device(fb_info); - device_destroy(fb_class, MKDEV(FB_MAJOR, i)); event.info = fb_info; fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event); @@ -1667,6 +1667,22 @@ static int do_unregister_framebuffer(struct fb_info *fb_info) return 0; } +int unlink_framebuffer(struct fb_info *fb_info) +{ + int i; + + i = fb_info->node; + if (i < 0 || i >= FB_MAX || registered_fb[i] != fb_info) + return -EINVAL; + + if (fb_info->dev) { + device_destroy(fb_class, MKDEV(FB_MAJOR, i)); + fb_info->dev = NULL; + } + return 0; +} +EXPORT_SYMBOL(unlink_framebuffer); + void remove_conflicting_framebuffers(struct apertures_struct *a, const char *name, bool primary) { diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c index 816a4fda04f5..415e9b2f43de 100644 --- a/drivers/video/udlfb.c +++ b/drivers/video/udlfb.c @@ -1666,7 +1666,7 @@ static void dlfb_usb_disconnect(struct usb_interface *interface) for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) device_remove_file(info->dev, &fb_device_attrs[i]); device_remove_bin_file(info->dev, &edid_attr); - + unlink_framebuffer(info); usb_set_intfdata(interface, NULL); /* if clients still have us open, will be freed on last close */ diff --git a/include/linux/fb.h b/include/linux/fb.h index 6a8274877171..f9d013d09bc7 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -997,6 +997,7 @@ extern ssize_t fb_sys_write(struct fb_info *info, const char __user *buf, /* drivers/video/fbmem.c */ extern int register_framebuffer(struct fb_info *fb_info); extern int unregister_framebuffer(struct fb_info *fb_info); +extern int unlink_framebuffer(struct fb_info *fb_info); extern void remove_conflicting_framebuffers(struct apertures_struct *a, const char *name, bool primary); extern int fb_prepare_logo(struct fb_info *fb_info, int rotate); -- 2.34.1