svn commit: r320901 - in head/sys: amd64/amd64 isa x86/isa

[Konstantin Belousov]

On Mon, Jul 17, 2017 at 10:29:33AM -0600, Ian Lepore wrote:
> I assumed the reason the efirt code was using the same mutex that
> protected access to the at rtc was because under the hood, the efi rt
> clock is really the same hardware too, accessed via bios code.

EFI spec states it explicitely, e.g. in the description of the GetTime()
function of the Time Services interface:

During runtime, if a PC-AT CMOS device is present in the platform the
caller must synchronize access to the device before calling GetTime().