Commit 8b3a149d authored by Ard Biesheuvel's avatar Ard Biesheuvel
Browse files

efi: earlycon: Reprobe after parsing config tables 



Commit 732ea9db ("efi: libstub: Move screen_info handling to common
code") reorganized the earlycon handling so that all architectures pass
the screen_info data via a EFI config table instead of populating struct
screen_info directly, as the latter is only possible when the EFI stub
is baked into the kernel (and not into the decompressor).

However, this means that struct screen_info may not have been populated
yet by the time the earlycon probe takes place, and this results in a
non-functional early console.

So let's probe again right after parsing the config tables and
populating struct screen_info. Note that this means that earlycon output
starts a bit later than before, and so it may fail to capture issues
that occur while doing the early EFI initialization.

Fixes: 732ea9db ("efi: libstub: Move screen_info handling to common code")
Reported-by: default avatarShawn Guo <shawn.guo@linaro.org>
Tested-by: default avatarShawn Guo <shawn.guo@linaro.org>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 3c66bb19

drivers/firmware/efi/earlycon.c

+13 −3
Original line number Diff line number Diff line
@@ -215,6 +215,14 @@ efi_earlycon_write(struct console *con, const char *str, unsigned int num) 
	}

}



static bool __initdata fb_probed;



void __init efi_earlycon_reprobe(void)

{

	if (fb_probed)

		setup_earlycon("efifb");

}



static int __init efi_earlycon_setup(struct earlycon_device *device,

				     const char *opt)

{
@@ -222,15 +230,17 @@ static int __init efi_earlycon_setup(struct earlycon_device *device, 
	u16 xres, yres;

	u32 i;



	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)

	fb_wb = opt && !strcmp(opt, "ram");



	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI) {

		fb_probed = true;

		return -ENODEV;

	}



	fb_base = screen_info.lfb_base;

	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)

		fb_base |= (u64)screen_info.ext_lfb_base << 32;



	fb_wb = opt && !strcmp(opt, "ram");



	si = &screen_info;

	xres = si->lfb_width;

	yres = si->lfb_height;

drivers/firmware/efi/efi-init.c

+3 −0
Original line number Diff line number Diff line
@@ -72,6 +72,9 @@ static void __init init_screen_info(void) 
		if (memblock_is_map_memory(screen_info.lfb_base))

			memblock_mark_nomap(screen_info.lfb_base,

					    screen_info.lfb_size);



		if (IS_ENABLED(CONFIG_EFI_EARLYCON))

			efi_earlycon_reprobe();

	}

}

include/linux/efi.h

+1 −0
Original line number Diff line number Diff line
@@ -693,6 +693,7 @@ efi_guid_to_str(efi_guid_t *guid, char *out) 
}



extern void efi_init (void);

extern void efi_earlycon_reprobe(void);

#ifdef CONFIG_EFI

extern void efi_enter_virtual_mode (void);	/* switch EFI to virtual mode, if possible */

#else