On 13 July 2015 at 13:01, Leif Lindholm leif.lindholm@linaro.org wrote:
Hi Haojian,
On Mon, Jul 13, 2015 at 10:15:09AM +0000, Haojian Zhuang wrote:
There's still something odd... I set a timeout of 3s in grub config and it takes closer to 10s in reality.
Actually it's 30 seconds if you set a timeout of 3s in grub config on hikey. I don't know whether there's the same issue on other ARM platforms.
I have seen this on some other platforms.
After debugging, I found the root cause. Now all ARM platforms set 10ms as timer periods. In grub, it tries to set 1 ms timer notifier. So here's the conflict. Timer notify will only be triggered when timer interrupt occurs. Even grub hope a timer event after 1ms, UEFI will provide the event notification after 10ms. The only way is to fix gEmbeddedTokenSpaceGuid.PcdTimerPeriod in UEFI.
It's not the timer period that is the problem. The timer period is mandated by the UEFI specification. But there may be a mismatch between the timer frequency and the frequency UEFI thinks the timer is running at.
This does indeed smell like a generic timer/EL3 botch. But I checked the HiKey dts, and it uses the same timer frequency there as it does in the HiKey .DSC. This still does not mean that ATF actually programs the correct value, but it suggests that UEFI and the kernel both override CNTFRQ to 12 MHz (IIRC)
I fix it in hikey UEFI now.
This sounds like a generic bug. Could you send an email to edk2-devel@lists.sourceforge.net, with Olivier.Martin@arm.com on cc?
Regards,
Leif _______________________________________________ Linaro-uefi mailing list Linaro-uefi@lists.linaro.org https://lists.linaro.org/mailman/listinfo/linaro-uefi