linux_dsm_epyc7002/include/video/udlfb.h
Mikulas Patocka 6b11f9d843 udlfb: fix sleeping inside spinlock
If a framebuffer device is used as a console, the rendering calls
(copyarea, fillrect, imageblit) may be done with the console spinlock
held. On udlfb, these function call dlfb_handle_damage that takes a
blocking semaphore before acquiring an URB.

In order to fix the bug, this patch changes the calls copyarea, fillrect
and imageblit to offload USB work to a workqueue.

A side effect of this patch is 3x improvement in console scrolling speed
because the device doesn't have to be updated after each copyarea call.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Bernie Thompson <bernie@plugable.com>
Cc: Ladislav Michl <ladis@linux-mips.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2019-04-01 17:46:56 +02:00

103 lines
2.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef UDLFB_H
#define UDLFB_H
/*
* TODO: Propose standard fb.h ioctl for reporting damage,
* using _IOWR() and one of the existing area structs from fb.h
* Consider these ioctls deprecated, but they're still used by the
* DisplayLink X server as yet - need both to be modified in tandem
* when new ioctl(s) are ready.
*/
#define DLFB_IOCTL_RETURN_EDID 0xAD
#define DLFB_IOCTL_REPORT_DAMAGE 0xAA
struct dloarea {
int x, y;
int w, h;
int x2, y2;
};
struct urb_node {
struct list_head entry;
struct dlfb_data *dlfb;
struct urb *urb;
};
struct urb_list {
struct list_head list;
spinlock_t lock;
struct semaphore limit_sem;
int available;
int count;
size_t size;
};
struct dlfb_data {
struct usb_device *udev;
struct fb_info *info;
struct urb_list urbs;
char *backing_buffer;
int fb_count;
bool virtualized; /* true when physical usb device not present */
atomic_t usb_active; /* 0 = update virtual buffer, but no usb traffic */
atomic_t lost_pixels; /* 1 = a render op failed. Need screen refresh */
char *edid; /* null until we read edid from hw or get from sysfs */
size_t edid_size;
int sku_pixel_limit;
int base16;
int base8;
u32 pseudo_palette[256];
int blank_mode; /*one of FB_BLANK_ */
int damage_x;
int damage_y;
int damage_x2;
int damage_y2;
spinlock_t damage_lock;
struct work_struct damage_work;
struct fb_ops ops;
/* blit-only rendering path metrics, exposed through sysfs */
atomic_t bytes_rendered; /* raw pixel-bytes driver asked to render */
atomic_t bytes_identical; /* saved effort with backbuffer comparison */
atomic_t bytes_sent; /* to usb, after compression including overhead */
atomic_t cpu_kcycles_used; /* transpired during pixel processing */
struct fb_var_screeninfo current_mode;
struct list_head deferred_free;
};
#define NR_USB_REQUEST_I2C_SUB_IO 0x02
#define NR_USB_REQUEST_CHANNEL 0x12
/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
#define BULK_SIZE 512
#define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
#define WRITES_IN_FLIGHT (4)
#define MAX_VENDOR_DESCRIPTOR_SIZE 256
#define GET_URB_TIMEOUT HZ
#define FREE_URB_TIMEOUT (HZ*2)
#define BPP 2
#define MAX_CMD_PIXELS 255
#define RLX_HEADER_BYTES 7
#define MIN_RLX_PIX_BYTES 4
#define MIN_RLX_CMD_BYTES (RLX_HEADER_BYTES + MIN_RLX_PIX_BYTES)
#define RLE_HEADER_BYTES 6
#define MIN_RLE_PIX_BYTES 3
#define MIN_RLE_CMD_BYTES (RLE_HEADER_BYTES + MIN_RLE_PIX_BYTES)
#define RAW_HEADER_BYTES 6
#define MIN_RAW_PIX_BYTES 2
#define MIN_RAW_CMD_BYTES (RAW_HEADER_BYTES + MIN_RAW_PIX_BYTES)
#define DL_DEFIO_WRITE_DELAY msecs_to_jiffies(HZ <= 300 ? 4 : 10) /* optimal value for 720p video */
#define DL_DEFIO_WRITE_DISABLE (HZ*60) /* "disable" with long delay */
/* remove these once align.h patch is taken into kernel */
#define DL_ALIGN_UP(x, a) ALIGN(x, a)
#define DL_ALIGN_DOWN(x, a) ALIGN_DOWN(x, a)
#endif