[0/2] ARM: mmp: PXA168 timer fixes

Message

Doug Brown Dec. 4, 2022, 12:51 a.m. UTC

This series contains a couple of bug fixes for the PXA168 timer. The
clock wasn't assigned in pxa168.dtsi which eventually resulted in a hang
at every boot after the clock was disabled. Also, the timer read
function wasn't waiting long enough to capture the new timer value,
which resulted in erroneous high CPU usage percent being reported with
CONFIG_NO_HZ_IDLE=y.

I don't have any other MMP systems to test with, but I suspect the timer
read delay problem also affected them. For example, the OLPC XO-4 kernel
disabled CONFIG_NO_HZ due to incorrect high CPU usage reporting:

http://dev.laptop.org/git/olpc-kernel/commit?h=arm-3.5&id=5bd2520f8f51fc44911ec7a86b84f41a1f3e384c

CCing [e-mail] because I didn't receive any responses when I
submitted these last time and was hoping these fixes could get merged.

Doug Brown (2):
  ARM: dts: pxa168: add timer reset and clock
  ARM: mmp: fix timer_read delay

 arch/arm/boot/dts/pxa168.dtsi |  2 ++
 arch/arm/mach-mmp/time.c      | 11 +++++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

Comments

[e-mail] Dec. 4, 2022, 12:20 p.m. UTC | #1

Hello:

This series was applied to soc/soc.git (for-next)
by Arnd Bergmann <[e-mail]>:

On Sat,  3 Dec 2022 16:51:15 -0800 you wrote:
> This series contains a couple of bug fixes for the PXA168 timer. The
> clock wasn't assigned in pxa168.dtsi which eventually resulted in a hang
> at every boot after the clock was disabled. Also, the timer read
> function wasn't waiting long enough to capture the new timer value,
> which resulted in erroneous high CPU usage percent being reported with
> CONFIG_NO_HZ_IDLE=y.
> 
> [...]

Here is the summary with links:
  - [1/2] ARM: dts: pxa168: add timer reset and clock
    https://git.kernel.org/soc/soc/c/7b3e7df92a06
  - [2/2] ARM: mmp: fix timer_read delay
    https://git.kernel.org/soc/soc/c/e348b4014c31

You are awesome, thank you!