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c014cae8e1
commit 68a958a915 upstream.
The udlfb driver maintained an open count and cleaned up itself when the
count reached zero. But the console is also counted in the reference count
- so, if the user unplugged the device, the open count would not drop to
zero and the driver stayed loaded with console attached. If the user
re-plugged the adapter, it would create a device /dev/fb1, show green
screen and the access to the console would be lost.
The framebuffer subsystem has reference counting on its own - in order to
fix the unplug bug, we rely the framebuffer reference counting. When the
user unplugs the adapter, we call unregister_framebuffer unconditionally.
unregister_framebuffer will unbind the console, wait until all users stop
using the framebuffer and then call the fb_destroy method. The fb_destroy
cleans up the USB driver.
This patch makes the following changes:
* Drop dlfb->kref and rely on implicit framebuffer reference counting
instead.
* dlfb_usb_disconnect calls unregister_framebuffer, the rest of driver
cleanup is done in the function dlfb_ops_destroy. dlfb_ops_destroy will
be called by the framebuffer subsystem when no processes have the
framebuffer open or mapped.
* We don't use workqueue during initialization, but initialize directly
from dlfb_usb_probe. The workqueue could race with dlfb_usb_disconnect
and this racing would produce various kinds of memory corruption.
* We use usb_get_dev and usb_put_dev to make sure that the USB subsystem
doesn't free the device under us.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
cc: Dave Airlie <airlied@redhat.com>
Cc: Bernie Thompson <bernie@plugable.com>,
Cc: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
97 lines
2.8 KiB
C
97 lines
2.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef UDLFB_H
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#define UDLFB_H
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/*
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* TODO: Propose standard fb.h ioctl for reporting damage,
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* using _IOWR() and one of the existing area structs from fb.h
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* Consider these ioctls deprecated, but they're still used by the
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* DisplayLink X server as yet - need both to be modified in tandem
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* when new ioctl(s) are ready.
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*/
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#define DLFB_IOCTL_RETURN_EDID 0xAD
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#define DLFB_IOCTL_REPORT_DAMAGE 0xAA
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struct dloarea {
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int x, y;
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int w, h;
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int x2, y2;
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};
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struct urb_node {
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struct list_head entry;
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struct dlfb_data *dlfb;
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struct urb *urb;
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};
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struct urb_list {
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struct list_head list;
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spinlock_t lock;
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struct semaphore limit_sem;
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int available;
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int count;
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size_t size;
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};
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struct dlfb_data {
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struct usb_device *udev;
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struct fb_info *info;
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struct urb_list urbs;
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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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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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char *edid; /* null until we read edid from hw or get from sysfs */
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size_t edid_size;
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int sku_pixel_limit;
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int base16;
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int base8;
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u32 pseudo_palette[256];
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int blank_mode; /*one of FB_BLANK_ */
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struct fb_ops ops;
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/* blit-only rendering path metrics, exposed through sysfs */
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atomic_t bytes_rendered; /* raw pixel-bytes driver asked to render */
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atomic_t bytes_identical; /* saved effort with backbuffer comparison */
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atomic_t bytes_sent; /* to usb, after compression including overhead */
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atomic_t cpu_kcycles_used; /* transpired during pixel processing */
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struct fb_var_screeninfo current_mode;
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struct list_head deferred_free;
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};
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#define NR_USB_REQUEST_I2C_SUB_IO 0x02
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#define NR_USB_REQUEST_CHANNEL 0x12
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/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
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#define BULK_SIZE 512
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#define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
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#define WRITES_IN_FLIGHT (4)
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#define MAX_VENDOR_DESCRIPTOR_SIZE 256
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#define GET_URB_TIMEOUT HZ
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#define FREE_URB_TIMEOUT (HZ*2)
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#define BPP 2
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#define MAX_CMD_PIXELS 255
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#define RLX_HEADER_BYTES 7
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#define MIN_RLX_PIX_BYTES 4
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#define MIN_RLX_CMD_BYTES (RLX_HEADER_BYTES + MIN_RLX_PIX_BYTES)
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#define RLE_HEADER_BYTES 6
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#define MIN_RLE_PIX_BYTES 3
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#define MIN_RLE_CMD_BYTES (RLE_HEADER_BYTES + MIN_RLE_PIX_BYTES)
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#define RAW_HEADER_BYTES 6
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#define MIN_RAW_PIX_BYTES 2
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#define MIN_RAW_CMD_BYTES (RAW_HEADER_BYTES + MIN_RAW_PIX_BYTES)
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#define DL_DEFIO_WRITE_DELAY msecs_to_jiffies(HZ <= 300 ? 4 : 10) /* optimal value for 720p video */
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#define DL_DEFIO_WRITE_DISABLE (HZ*60) /* "disable" with long delay */
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/* remove these once align.h patch is taken into kernel */
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#define DL_ALIGN_UP(x, a) ALIGN(x, a)
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#define DL_ALIGN_DOWN(x, a) ALIGN_DOWN(x, a)
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#endif
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