kernel-5.15/0624-efi-rtc-avoid-calling-efi.get_time-on-Baikal-M-SoC.patch

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From b7bf519f24c2160c092ce8b6c9f72ead91dbe8cb Mon Sep 17 00:00:00 2001
From: Alexey Sheplyakov <asheplyakov@altlinux.org>
Date: Thu, 8 Oct 2020 18:31:28 +0400
Subject: [PATCH 624/634] efi-rtc: avoid calling efi.get_time on Baikal-M SoC
Old versions of Baikal-M UEFI (before SDK-M 4.4) do NOT provide
get_time at the runtime (not even as a stub), hence calling it
results in an Oops.
X-DONTUPSTREAM
X-legacy
---
drivers/rtc/rtc-efi.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c
index 138c5e004..af2328022 100644
--- a/drivers/rtc/rtc-efi.c
+++ b/drivers/rtc/rtc-efi.c
@@ -17,6 +17,7 @@
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/efi.h>
+#include <linux/of.h>
#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
@@ -257,6 +258,14 @@ static int __init efi_rtc_probe(struct platform_device *dev)
efi_time_t eft;
efi_time_cap_t cap;
+#ifdef CONFIG_OF
+ /* efi.get_time is not always safe to call since some UEFI
+ * implementations do not privde get_time at runtime. */
+ if (of_device_is_compatible(of_root, "baikal,baikal-m")) {
+ dev_err(&dev->dev, "Baikal-M UEFI has no get_time\n");
+ return -ENODEV;
+ }
+#endif
/* First check if the RTC is usable */
if (efi.get_time(&eft, &cap) != EFI_SUCCESS)
return -ENODEV;
--
2.33.2