Description of problem: PL031 is a real time clock. Although it is not found on real hardware AFAICT, it is emulated by qemu-system-aarch64 and therefore it's a useful way to get wallclock time in VMs. There is no kvmclock on !x86, and without PL031 the VM's time will be set to 1/1/1970 for a long time (until you start ntpd which is quite a long time into the boot process, and never happens in libguestfs VMs). I have enabled this option in my kernel and tested it booting on both the real hardware and inside a VM. It has no effect on the real hardware. In the VM it ensures that the wallclock is set correctly close to boot. You will see this message during VM boot: [ 0.742380] rtc-pl031 90010000.pl031: rtc core: registered pl031 as rtc0 [ 0.789316] rtc-pl031 90010000.pl031: setting system clock to 2014-07-28 14:21:39 UTC (1406557299) Version-Release number of selected component (if applicable): 3.16.0-0.rc6.git3.1.fc22.aarch64 How reproducible: 100% Steps to Reproduce: 1. Start a KVM VM. 2. Observe the clock in the VM. It is set to 1/1/1970.
CONFIG =y or =m ?
(In reply to Don Dutile from comment #1) > CONFIG =y or =m ? I'm testing it compiled in (=y). It doesn't affect boot on the aarch64 real hardware. I believe it'd be better for the clock to be compiled in so that it can be initialized as soon as possible.
I've been testing this patch for months. What can I do to get this actioned? I will push it myself if permitted. diff --git a/config-arm64 b/config-arm64 index bdcc9b9..eac2b9a 100644 --- a/config-arm64 +++ b/config-arm64 @@ -52,7 +52,7 @@ CONFIG_NFS_USE_KERNEL_DNS=y # CONFIG_PL330_DMA is not set CONFIG_RCU_FANOUT=64 # CONFIG_RTC_DRV_PL030 is not set -# CONFIG_RTC_DRV_PL031 is not set +CONFIG_RTC_DRV_PL031=y CONFIG_SERIAL_8250_DMA=y # CONFIG_SERIAL_AMBA_PL010 is not set CONFIG_SPARSE_IRQ=y
I'll change it in today's rawhide build.
The needinfo request[s] on this closed bug have been removed as they have been unresolved for 1000 days