On 13/06/2024 21:18, Geert Uytterhoeven wrote:
Re-use the existing support for boot-up logos to draw a monochrome
graphical logo in the DRM panic handler. When no suitable graphical
logo is available, the code falls back to the ASCII art penguin logo.
Note that all graphical boot-up logos are freed during late kernel
initialization, hence a copy must be made for later use.
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
v2:
- Rebased,
- Inline trivial draw_logo_mono().
---
drivers/gpu/drm/drm_panic.c | 65 +++++++++++++++++++++++++++++++++----
drivers/video/logo/Kconfig | 2 ++
2 files changed, 60 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index f7e22b69bb25d3be..af30f243b2802ad7 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -7,11 +7,15 @@
*/
#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>
@@ -88,6 +92,42 @@ static const struct drm_panic_line logo_ascii[] = {
PANIC_LINE(" \\___)=(___/"),
};
+#ifdef CONFIG_LOGO
+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
I didn't notice that the first time, but the core drm can be built as a
module.
That means this will leak memory each time the module is removed.
But to solve the circular dependency between drm_kms_helper and
drm_panic, one solution is to depends on drm core to be built-in.
In this case there won't be a leak.
So depending on how we solve the circular dependency, it can be acceptable.
--
Jocelyn
