[PATCH 4.9 16/51] x86/reboot, efi: Use EFI reboot for Acer TravelMate X514-51T

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

[ Upstream commit 0082517fa4bce073e7cf542633439f26538a14cc ]

Upon reboot, the Acer TravelMate X514-51T laptop appears to complete the
shutdown process, but then it hangs in BIOS POST with a black screen.

The problem is intermittent - at some points it has appeared related to
Secure Boot settings or different kernel builds, but ultimately we have
not been able to identify the exact conditions that trigger the issue to
come and go.

Besides, the EFI mode cannot be disabled in the BIOS of this model.

However, after extensive testing, we observe that using the EFI reboot
method reliably avoids the issue in all cases.

So add a boot time quirk to use EFI reboot on such systems.

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=203119
Signed-off-by: Jian-Hong Pan <jian-hong@endlessm.com>
Signed-off-by: Daniel Drake <drake@endlessm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: linux@endlessm.com
Link: http://lkml.kernel.org/r/20190412080152.3718-1-jian-hong@endlessm.com
[ Fix !CONFIG_EFI build failure, clarify the code and the changelog a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/kernel/reboot.c | 21 +++++++++++++++++++++
 include/linux/efi.h      |  7 ++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 4a12362a194af..c55b11fe8e9f6 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -82,6 +82,19 @@ static int __init set_bios_reboot(const struct dmi_system_id *d)
 	return 0;
 }
 
+/*
+ * Some machines don't handle the default ACPI reboot method and
+ * require the EFI reboot method:
+ */
+static int __init set_efi_reboot(const struct dmi_system_id *d)
+{
+	if (reboot_type != BOOT_EFI && !efi_runtime_disabled()) {
+		reboot_type = BOOT_EFI;
+		pr_info("%s series board detected. Selecting EFI-method for reboot.\n", d->ident);
+	}
+	return 0;
+}
+
 void __noreturn machine_real_restart(unsigned int type)
 {
 	local_irq_disable();
@@ -167,6 +180,14 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
 			DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
 		},
 	},
+	{	/* Handle reboot issue on Acer TravelMate X514-51T */
+		.callback = set_efi_reboot,
+		.ident = "Acer TravelMate X514-51T",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"),
+		},
+	},
 
 	/* Apple */
 	{	/* Handle problems with rebooting on Apple MacBook5 */
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 80b1b8faf503f..e6711bf9f0d12 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1433,7 +1433,12 @@ efi_status_t efi_setup_gop(efi_system_table_t *sys_table_arg,
 			   struct screen_info *si, efi_guid_t *proto,
 			   unsigned long size);
 
-bool efi_runtime_disabled(void);
+#ifdef CONFIG_EFI
+extern bool efi_runtime_disabled(void);
+#else
+static inline bool efi_runtime_disabled(void) { return true; }
+#endif
+
 extern void efi_call_virt_check_flags(unsigned long flags, const char *call);
 
 /*
-- 
2.20.1