// SPDX-License-Identifier: GPL-2.0 or MIT
/*
* Copyright (c) 2023 Red Hat.
* Author: Jocelyn Falempe <[email protected]>
* inspired by the drm_log driver from David Herrmann <[email protected]>
* Tux Ascii art taken from cowsay written by Tony Monroe
*/
#include <linux/font.h>
#include <linux/init.h>
#include <linux/iosys-map.h>
#include <linux/kdebug.h>
#include <linux/kmsg_dump.h>
#include <linux/linux_logo.h>
#include <linux/list.h>
#include <linux/math.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/printk.h>
#include <linux/types.h>
#include <drm/drm_drv.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_panic.h>
#include <drm/drm_plane.h>
#include <drm/drm_print.h>
MODULE_AUTHOR("Jocelyn Falempe");
MODULE_DESCRIPTION("DRM panic handler");
MODULE_LICENSE("GPL");
static char drm_panic_screen[16] = CONFIG_DRM_PANIC_SCREEN;
module_param_string(panic_screen, drm_panic_screen, sizeof(drm_panic_screen), 0644);
MODULE_PARM_DESC(panic_screen,
"Choose what will be displayed by drm_panic, 'user' or 'kmsg' [default="
CONFIG_DRM_PANIC_SCREEN "]");
/**
* DOC: overview
*
* To enable DRM panic for a driver, the primary plane must implement a
* &drm_plane_helper_funcs.get_scanout_buffer helper function. It is then
* automatically registered to the drm panic handler.
* When a panic occurs, the &drm_plane_helper_funcs.get_scanout_buffer will be
* called, and the driver can provide a framebuffer so the panic handler can
* draw the panic screen on it. Currently only linear buffer and a few color
* formats are supported.
* Optionally the driver can also provide a &drm_plane_helper_funcs.panic_flush
* callback, that will be called after that, to send additional commands to the
* hardware to make the scanout buffer visible.
*/
/*
* This module displays a user friendly message on screen when a kernel panic
* occurs. This is conflicting with fbcon, so you can only enable it when fbcon
* is disabled.
* It's intended for end-user, so have minimal technical/debug information.
*
* Implementation details:
*
* It is a panic handler, so it can't take lock, allocate memory, run tasks/irq,
* or attempt to sleep. It's a best effort, and it may not be able to display
* the message in all situations (like if the panic occurs in the middle of a
* modesetting).
* It will display only one static frame, so performance optimizations are low
* priority as the machine is already in an unusable state.
*/
struct drm_panic_line {
u32 len;
const char *txt;
};
#define PANIC_LINE(s) {.len = sizeof(s) - 1, .txt = s}
static struct drm_panic_line panic_msg[] = {
PANIC_LINE("KERNEL PANIC !"),
PANIC_LINE(""),
PANIC_LINE("Please reboot your computer."),
};
static const struct drm_panic_line logo_ascii[] = {
PANIC_LINE(" .--. _"),
PANIC_LINE(" |o_o | | |"),
PANIC_LINE(" |:_/ | | |"),
PANIC_LINE(" // \\ \\ |_|"),
PANIC_LINE(" (| | ) _"),
PANIC_LINE(" /'\\_ _/`\\ (_)"),
PANIC_LINE(" \\___)=(___/"),
};
#if defined(CONFIG_LOGO) && !defined(MODULE)
static const struct linux_logo *logo_mono;
static int drm_panic_setup_logo(void)
{
const struct linux_logo *logo = fb_find_logo(1);
const unsigned char *logo_data;
struct linux_logo *logo_dup;
if (!logo || logo->type != LINUX_LOGO_MONO)
return 0;
/* The logo is __init, so we must make a copy for later use */
logo_data = kmemdup(logo->data,
size_mul(DIV_ROUND_UP(logo->width, BITS_PER_BYTE), logo->height),
GFP_KERNEL);
if (!logo_data)
return -ENOMEM;
logo_dup = kmemdup(logo, sizeof(*logo), GFP_KERNEL);
if (!logo_dup) {
kfree(logo_data);
return -ENOMEM;
}
logo_dup->data = logo_data;
logo_mono = logo_dup;
return 0;
}
device_initcall(drm_panic_setup_logo);
#else
#define logo_mono ((const struct linux_logo *)NULL)
#endif
/*
* Color conversion
*/
static u16 convert_xrgb8888_to_rgb565(u32 pix)
{
return ((pix & 0x00F80000) >> 8) |
((pix & 0x0000FC00) >> 5) |
((pix & 0x000000F8) >> 3);
}
static u16 convert_xrgb8888_to_rgba5551(u32 pix)
{
return ((pix & 0x00f80000) >> 8) |
((pix & 0x0000f800) >> 5) |
((pix & 0x000000f8) >> 2) |
BIT(0); /* set alpha bit */
}
static u16 convert_xrgb8888_to_xrgb1555(u32 pix)
{
return ((pix & 0x00f80000) >> 9) |
((pix & 0x0000f800) >> 6) |
((pix & 0x000000f8) >> 3);
}
static u16 convert_xrgb8888_to_argb1555(u32 pix)
{
return BIT(15) | /* set alpha bit */
((pix & 0x00f80000) >> 9) |
((pix & 0x0000f800) >> 6) |
((pix & 0x000000f8) >> 3);
}
static u32 convert_xrgb8888_to_argb8888(u32 pix)
{
return pix | GENMASK(31, 24); /* fill alpha bits */
}
static u32 convert_xrgb8888_to_xbgr8888(u32 pix)
{
return ((pix & 0x00ff0000) >> 16) << 0 |
((pix & 0x0000ff00) >> 8) << 8 |
((pix & 0x000000ff) >> 0) << 16 |
((pix & 0xff000000) >> 24) << 24;
}
static u32 convert_xrgb8888_to_abgr8888(u32 pix)
{
return ((pix & 0x00ff0000) >> 16) << 0 |
((pix & 0x0000ff00) >> 8) << 8 |
((pix & 0x000000ff) >> 0) << 16 |
GENMASK(31, 24); /* fill alpha bits */
}
static u32 convert_xrgb8888_to_xrgb2101010(u32 pix)
{
pix = ((pix & 0x000000FF) << 2) |
((pix & 0x0000FF00) << 4) |
((pix & 0x00FF0000) << 6);
return pix | ((pix >> 8) & 0x00300C03);
}
static u32 convert_xrgb8888_to_argb2101010(u32 pix)
{
pix = ((pix & 0x000000FF) << 2) |
((pix & 0x0000FF00) << 4) |
((pix & 0x00FF0000) << 6);
return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);
}
/*
* convert_from_xrgb8888 - convert one pixel from xrgb8888 to the desired format
* @color: input color, in xrgb8888 format
* @format: output format
*
* Returns:
* Color in the format specified, casted to u32.
* Or 0 if the format is not supported.
*/
static u32 convert_from_xrgb8888(u32 color, u32 format)
{
switch (format) {
case DRM_FORMAT_RGB565:
return convert_xrgb8888_to_rgb565(color);
case DRM_FORMAT_RGBA5551:
return convert_xrgb8888_to_rgba5551(color);
case DRM_FORMAT_XRGB1555:
return convert_xrgb8888_to_xrgb1555(color);
case DRM_FORMAT_ARGB1555:
return convert_xrgb8888_to_argb1555(color);
case DRM_FORMAT_RGB888:
case DRM_FORMAT_XRGB8888:
return color;
case DRM_FORMAT_ARGB8888:
return convert_xrgb8888_to_argb8888(color);
case DRM_FORMAT_XBGR8888:
return convert_xrgb8888_to_xbgr8888(color);
case DRM_FORMAT_ABGR8888:
return convert_xrgb8888_to_abgr8888(color);
case DRM_FORMAT_XRGB2101010:
return convert_xrgb8888_to_xrgb2101010(color);
case DRM_FORMAT_ARGB2101010:
return convert_xrgb8888_to_argb2101010(color);
default:
WARN_ONCE(1, "Can't convert to %p4cc\n", &format);
return 0;
}
}
/*
* Blit & Fill
*/
/* check if the pixel at coord x,y is 1 (foreground) or 0 (background) */
static bool drm_panic_is_pixel_fg(const u8 *sbuf8, unsigned int spitch, int x, int y)
{
return (sbuf8[(y * spitch) + x / 8] & (0x80 >> (x % 8))) != 0;
}
static void drm_panic_blit16(struct iosys_map *dmap, unsigned int dpitch,
const u8 *sbuf8, unsigned int spitch,
unsigned int height, unsigned int width,
u16 fg16)
{
unsigned int y, x;
for (y = 0; y < height; y++)
for (x = 0; x < width; x++)
if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y))
iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, fg16);
}
static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,
const u8 *sbuf8, unsigned int spitch,
unsigned int height, unsigned int width,
u32 fg32)
{
unsigned int y, x;
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
u32 off = y * dpitch + x * 3;
if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y)) {
/* write blue-green-red to output in little endianness */
iosys_map_wr(dmap, off, u8, (fg32 & 0x000000FF) >> 0);
iosys_map_wr(dmap, off + 1, u8, (fg32 & 0x0000FF00) >> 8);
iosys_map_wr(dmap, off + 2, u8, (fg32 & 0x00FF0000) >> 16);
}
}
}
}
static void drm_panic_blit32(struct iosys_map *dmap, unsigned int dpitch,
const u8 *sbuf8, unsigned int spitch,
unsigned int height, unsigned int width,
u32 fg32)
{
unsigned int y, x;
for (y = 0; y < height; y++)
for (x = 0; x < width; x++)
if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y))
iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, fg32);
}
static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip,
const u8 *sbuf8, unsigned int spitch, u32 fg_color)
{
unsigned int y, x;
for (y = 0; y < drm_rect_height(clip); y++)
for (x = 0; x < drm_rect_width(clip); x++)
if (drm_panic_is_pixel_fg(sbuf8, spitch, x, y))
sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color);
}
/*
* drm_panic_blit - convert a monochrome image to a linear framebuffer
* @sb: destination scanout buffer
* @clip: destination rectangle
* @sbuf8: source buffer, in monochrome format, 8 pixels per byte.
* @spitch: source pitch in bytes
* @fg_color: foreground color, in destination format
*
* This can be used to draw a font character, which is a monochrome image, to a
* framebuffer in other supported format.
*/
static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
const u8 *sbuf8, unsigned int spitch, u32 fg_color)
{
struct iosys_map map;
if (sb->set_pixel)
return drm_panic_blit_pixel(sb, clip, sbuf8, spitch, fg_color);
map = sb->map[0];
iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);
switch (sb->format->cpp[0]) {
case 2:
drm_panic_blit16(&map, sb->pitch[0], sbuf8, spitch,
drm_rect_height(clip), drm_rect_width(clip), fg_color);
break;
case 3:
drm_panic_blit24(&map, sb->pitch[0], sbuf8, spitch,
drm_rect_height(clip), drm_rect_width(clip), fg_color);
break;
case 4:
drm_panic_blit32(&map, sb->pitch[0], sbuf8, spitch,
drm_rect_height(clip), drm_rect_width(clip), fg_color);
break;
default:
WARN_ONCE(1, "Can't blit with pixel width %d\n", sb->format->cpp[0]);
}
}
static void drm_panic_fill16(struct iosys_map *dmap, unsigned int dpitch,
unsigned int height, unsigned int width,
u16 color)
{
unsigned int y, x;
for (y = 0; y < height; y++)
for (x = 0; x < width; x++)
iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, color);
}
static void drm_panic_fill24(struct iosys_map *dmap, unsigned int dpitch,
unsigned int height, unsigned int width,
u32 color)
{
unsigned int y, x;
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
unsigned int off = y * dpitch + x * 3;
/* write blue-green-red to output in little endianness */
iosys_map_wr(dmap, off, u8, (color & 0x000000FF) >> 0);
iosys_map_wr(dmap, off + 1, u8, (color & 0x0000FF00) >> 8);
iosys_map_wr(dmap, off + 2, u8, (color & 0x00FF0000) >> 16);
}
}
}
static void drm_panic_fill32(struct iosys_map *dmap, unsigned int dpitch,
unsigned int height, unsigned int width,
u32 color)
{
unsigned int y, x;
for (y = 0; y < height; y++)
for (x = 0; x < width; x++)
iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, color);
}
static void drm_panic_fill_pixel(struct drm_scanout_buffer *sb,
struct drm_rect *clip,
u32 color)
{
unsigned int y, x;
for (y = 0; y < drm_rect_height(clip); y++)
for (x = 0; x < drm_rect_width(clip); x++)
sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, color);
}
/*
* drm_panic_fill - Fill a rectangle with a color
* @sb: destination scanout buffer
* @clip: destination rectangle
* @color: foreground color, in destination format
*
* Fill a rectangle with a color, in a linear framebuffer.
*/
static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip,
u32 color)
{
struct iosys_map map;
if (sb->set_pixel)
return drm_panic_fill_pixel(sb, clip, color);
map = sb->map[0];
iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]);
switch (sb->format->cpp[0]) {
case 2:
drm_panic_fill16(&map, sb->pitch[0], drm_rect_height(clip),
drm_rect_width(clip), color);
break;
case 3:
drm_panic_fill24(&map, sb->pitch[0], drm_rect_height(clip),
drm_rect_width(clip), color);
break;
case 4:
drm_panic_fill32(&map, sb->pitch[0], drm_rect_height(clip),
drm_rect_width(clip), color);
break;
default:
WARN_ONCE(1, "Can't fill with pixel width %d\n", sb->format->cpp[0]);
}
}
static const u8 *get_char_bitmap(const struct font_desc *font, char c, size_t font_pitch)
{
return font->data + (c * font->height) * font_pitch;
}
static unsigned int get_max_line_len(const struct drm_panic_line *lines, int len)
{
int i;
unsigned int max = 0;
for (i = 0; i < len; i++)
max = max(lines[i].len, max);
return max;
}
/*
* Draw a text in a rectangle on a framebuffer. The text is truncated if it overflows the rectangle
*/
static void draw_txt_rectangle(struct drm_scanout_buffer *sb,
const struct font_desc *font,
const struct drm_panic_line *msg,
unsigned int msg_lines,
bool centered,
struct drm_rect *clip,
u32 color)
{
int i, j;
const u8 *src;
size_t font_pitch = DIV_ROUND_UP(font->width, 8);
struct drm_rect rec;
msg_lines = min(msg_lines, drm_rect_height(clip) / font->height);
for (i = 0; i < msg_lines; i++) {
size_t line_len = min(msg[i].len, drm_rect_width(clip) / font->width);
rec.y1 = clip->y1 + i * font->height;
rec.y2 = rec.y1 + font->height;
rec.x1 = clip->x1;
if (centered)
rec.x1 += (drm_rect_width(clip) - (line_len * font->width)) / 2;
for (j = 0; j < line_len; j++) {
src = get_char_bitmap(font, msg[i].txt[j], font_pitch);
rec.x2 = rec.x1 + font->width;
drm_panic_blit(sb, &rec, src, font_pitch, color);
rec.x1 += font->width;
}
}
}
static void draw_panic_static_user(struct drm_scanout_buffer *sb)
{
size_t msg_lines = ARRAY_SIZE(panic_msg);
size_t logo_ascii_lines = ARRAY_SIZE(logo_ascii);
u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
struct drm_rect r_screen, r_logo, r_msg;
unsigned int logo_width, logo_height;
if (!font)
return;
r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
if (logo_mono) {
logo_width = logo_mono->width;
logo_height = logo_mono->height;
} else {
logo_width = get_max_line_len(logo_ascii, logo_ascii_lines) * font->width;
logo_height = logo_ascii_lines * font->height;
}
r_logo = DRM_RECT_INIT(0, 0, logo_width, logo_height);
r_msg = DRM_RECT_INIT(0, 0,
min(get_max_line_len(panic_msg, msg_lines) * font->width, sb->width),
min(msg_lines * font->height, sb->height));
/* Center the panic message */
drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, (sb->height - r_msg.y2) / 2);
/* Fill with the background color, and draw text on top */
drm_panic_fill(sb, &r_screen, bg_color);
if ((r_msg.x1 >= logo_width || r_msg.y1 >= logo_height) &&
logo_width <= sb->width && logo_height <= sb->height) {
if (logo_mono)
drm_panic_blit(sb, &r_logo, logo_mono->data, DIV_ROUND_UP(logo_width, 8),
fg_color);
else
draw_txt_rectangle(sb, font, logo_ascii, logo_ascii_lines, false, &r_logo,
fg_color);
}
draw_txt_rectangle(sb, font, panic_msg, msg_lines, true, &r_msg, fg_color);
}
/*
* Draw one line of kmsg, and handle wrapping if it won't fit in the screen width.
* Return the y-offset of the next line.
*/
static int draw_line_with_wrap(struct drm_scanout_buffer *sb, const struct font_desc *font,
struct drm_panic_line *line, int yoffset, u32 fg_color)
{
int chars_per_row = sb->width / font->width;
struct drm_rect r_txt = DRM_RECT_INIT(0, yoffset, sb->width, sb->height);
struct drm_panic_line line_wrap;
if (line->len > chars_per_row) {
line_wrap.len = line->len % chars_per_row;
line_wrap.txt = line->txt + line->len - line_wrap.len;
draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color);
r_txt.y1 -= font->height;
if (r_txt.y1 < 0)
return r_txt.y1;
while (line_wrap.txt > line->txt) {
line_wrap.txt -= chars_per_row;
line_wrap.len = chars_per_row;
draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color);
r_txt.y1 -= font->height;
if (r_txt.y1 < 0)
return r_txt.y1;
}
} else {
draw_txt_rectangle(sb, font, line, 1, false, &r_txt, fg_color);
r_txt.y1 -= font->height;
}
return r_txt.y1;
}
/*
* Draw the kmsg buffer to the screen, starting from the youngest message at the bottom,
* and going up until reaching the top of the screen.
*/
static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb)
{
u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
struct drm_rect r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
struct kmsg_dump_iter iter;
char kmsg_buf[512];
size_t kmsg_len;
struct drm_panic_line line;
int yoffset;
if (!font)
return;
yoffset = sb->height - font->height - (sb->height % font->height) / 2;
/* Fill with the background color, and draw text on top */
drm_panic_fill(sb, &r_screen, bg_color);
kmsg_dump_rewind(&iter);
while (kmsg_dump_get_buffer(&iter, false, kmsg_buf, sizeof(kmsg_buf), &kmsg_len)) {
char *start;
char *end;
/* ignore terminating NUL and newline */
start = kmsg_buf + kmsg_len - 2;
end = kmsg_buf + kmsg_len - 1;
while (start > kmsg_buf && yoffset >= 0) {
while (start > kmsg_buf && *start != '\n')
start--;
/* don't count the newline character */
line.txt = start + (start == kmsg_buf ? 0 : 1);
line.len = end - line.txt;
yoffset = draw_line_with_wrap(sb, font, &line, yoffset, fg_color);
end = start;
start--;
}
}
}
/*
* drm_panic_is_format_supported()
* @format: a fourcc color code
* Returns: true if supported, false otherwise.
*
* Check if drm_panic will be able to use this color format.
*/
static bool drm_panic_is_format_supported(const struct drm_format_info *format)
{
if (format->num_planes != 1)
return false;
return convert_from_xrgb8888(0xffffff, format->format) != 0;
}
static void draw_panic_dispatch(struct drm_scanout_buffer *sb)
{
if (!strcmp(drm_panic_screen, "kmsg")) {
draw_panic_static_kmsg(sb);
} else {
draw_panic_static_user(sb);
}
}
static void draw_panic_plane(struct drm_plane *plane)
{
struct drm_scanout_buffer sb = { };
int ret;
unsigned long flags;
if (!drm_panic_trylock(plane->dev, flags))
return;
ret = plane->helper_private->get_scanout_buffer(plane, &sb);
if (!ret && drm_panic_is_format_supported(sb.format)) {
draw_panic_dispatch(&sb);
if (plane->helper_private->panic_flush)
plane->helper_private->panic_flush(plane);
}
drm_panic_unlock(plane->dev, flags);
}
static struct drm_plane *to_drm_plane(struct kmsg_dumper *kd)
{
return container_of(kd, struct drm_plane, kmsg_panic);
}
static void drm_panic(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason)
{
struct drm_plane *plane = to_drm_plane(dumper);
if (reason == KMSG_DUMP_PANIC)
draw_panic_plane(plane);
}
/*
* DEBUG FS, This is currently unsafe.
* Create one file per plane, so it's possible to debug one plane at a time.
* TODO: It would be better to emulate an NMI context.
*/
#ifdef CONFIG_DRM_PANIC_DEBUG
#include <linux/debugfs.h>
static ssize_t debugfs_trigger_write(struct file *file, const char __user *user_buf,
size_t count, loff_t *ppos)
{
bool run;
if (kstrtobool_from_user(user_buf, count, &run) == 0 && run) {
struct drm_plane *plane = file->private_data;
draw_panic_plane(plane);
}
return count;
}
static const struct file_operations dbg_drm_panic_ops = {
.owner = THIS_MODULE,
.write = debugfs_trigger_write,
.open = simple_open,
};
static void debugfs_register_plane(struct drm_plane *plane, int index)
{
char fname[32];
snprintf(fname, 32, "drm_panic_plane_%d", index);
debugfs_create_file(fname, 0200, plane->dev->debugfs_root,
plane, &dbg_drm_panic_ops);
}
#else
static void debugfs_register_plane(struct drm_plane *plane, int index) {}
#endif /* CONFIG_DRM_PANIC_DEBUG */
/**
* drm_panic_register() - Initialize DRM panic for a device
* @dev: the drm device on which the panic screen will be displayed.
*/
void drm_panic_register(struct drm_device *dev)
{
struct drm_plane *plane;
int registered_plane = 0;
if (!dev->mode_config.num_total_plane)
return;
drm_for_each_plane(plane, dev) {
if (!plane->helper_private || !plane->helper_private->get_scanout_buffer)
continue;
plane->kmsg_panic.dump = drm_panic;
plane->kmsg_panic.max_reason = KMSG_DUMP_PANIC;
if (kmsg_dump_register(&plane->kmsg_panic))
drm_warn(dev, "Failed to register panic handler\n");
else {
debugfs_register_plane(plane, registered_plane);
registered_plane++;
}
}
if (registered_plane)
drm_info(dev, "Registered %d planes with drm panic\n", registered_plane);
}
EXPORT_SYMBOL(drm_panic_register);
/**
* drm_panic_unregister()
* @dev: the drm device previously registered.
*/
void drm_panic_unregister(struct drm_device *dev)
{
struct drm_plane *plane;
if (!dev->mode_config.num_total_plane)
return;
drm_for_each_plane(plane, dev) {
if (!plane->helper_private || !plane->helper_private->get_scanout_buffer)
continue;
kmsg_dump_unregister(&plane->kmsg_panic);
}
}
EXPORT_SYMBOL(drm_panic_unregister);
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