(tiny) patch review: return if RTC diag fails

[Emile `iMil' Heitor <imil%home.imil.net@localhost>]

Currently in sys/arch/x86/isa/clock.c startrtclock(), the function
continues to call tc_init() even when mc146818_read(NULL, NVRAM_DIAG)
fails. This causes the system to hang on qemu/microvm when rtc=on is
not specified.

My proposal is to return if RTC BIOS diagnostic fails:

ef4df237b7db39630f5400b6f0f193eebe1afe87 Return if RTC BIOS fails
diff --git a/sys/arch/x86/isa/clock.c b/sys/arch/x86/isa/clock.c
index 8305818c109..4c9445227f4 100644
--- a/sys/arch/x86/isa/clock.c
+++ b/sys/arch/x86/isa/clock.c
@@ -335,6 +335,7 @@ startrtclock(void)
 		char bits[128];
 		snprintb(bits, sizeof(bits), NVRAM_DIAG_BITS, s);
 		printf("RTC BIOS diagnostic error %s\n", bits);
+		return;
 	}

 	tc_init(&i8254_timecounter);

Thoughts?

------------------------------------------------------------------------
Emile `iMil' Heitor <imil@{home.imil.net,NetBSD.org}> | https://imil.net