Re: [Qemu-arm] [PATCH] hw/char/cmsdk-apb-timer: Correctly identify and set one-shot mode

[Peter Maydell]

On 2 July 2018 at 19:37, Guenter Roeck <address@hidden> wrote:
> Please try http://server.roeck-us.net/qemu/an385/
>
> vmlinux is plain v4.18-rc3 compiled with the provided defconfig and
> the provided toolchain (position independent, created with buildroot).
> defconfig is mps2_defconfig+CONFIG_BLK_DEV_INITRD=y. Older kernels work
> as well (I tested as far back as 4.9.y), with the same configuration.
>
> qemu is from the master-local branch in my repository, built with
> https://github.com/groeck/linux-build-test/blob/master/qemu/buildall.sh.
>
> The boot wrapper was generated from
> https://github.com/groeck/linux-build-test/tree/master/rootfs/arm/arm-m3-bootwrapper/.
>
> run.sh should boot the system into a shell (at least it does for me).

Thanks. Unfortunately I tried running that a bunch of times with a
version of your QEMU with the 'set one-shot mode' patch reverted,
and it still booted every time.

However, I think I agree with you that it's better for the timer
device to avoid doing things that result in the ptimer code emitting
warnings rather than just dropping the ptimer warning, so I'm going
to take this patch upstream.

I also sorted through some of the other corner case issues
(eg restarting a stopped one-shot timer by writing to VALUE,
and whether an interrupt should be generated if VALUE is
written as zero). I'm going to send a patchset in a moment that
includes this patch and those fixes. I've tested that set by
applying it to your master-local/ branch and using your testcase
here, as well as by using my buildroot/uclinux image on an
upstream QEMU (and a few other RTOS images I had to hand).

thanks
-- PMM