Hi,

* Drew Fustini [off-list ref] [220129 21:05]:

On Tue, Mar 23, 2021 at 09:43:26AM +0200, Tony Lindgren wrote:

quoted

There is a timer wrap issue on dra7 for the ARM architected timer.
In a typical clock configuration the timer fails to wrap after 388 days.

To work around the issue, we need to use timer-ti-dm percpu timers instead.

Let's configure dmtimer3 and 4 as percpu timers by default, and warn about
the issue if the dtb is not configured properly.

Hi Tony,

This causes a conflict for IPU2 which is using timer 3 and 4.

From arch/arm/boot/dts/dra7-ipu-dsp-common.dtsi:

  &ipu2 {
          mboxes = <&mailbox6 &mbox_ipu2_ipc3x>;
          ti,timers = <&timer3>;
          ti,watchdog-timers = <&timer4>, <&timer9>;
  };

OK, sorry I missed that part.

I noticed an error ("could not get timer platform device") when booting
mainline on a BeagleBoard X15 (AM578):

  omap-rproc 55020000.ipu: assigned reserved memory node ipu2-memory@95800000
  remoteproc remoteproc1: 55020000.ipu is available
  remoteproc remoteproc1: powering up 55020000.ipu
  remoteproc remoteproc1: Booting fw image dra7-ipu2-fw.xem4, size 3747220
  omap-rproc 55020000.ipu: could not get timer platform device
  omap-rproc 55020000.ipu: omap_rproc_enable_timers failed: -19
  remoteproc remoteproc1: can't start rproc 55020000.ipu: -19

I switched this errata fix to use timer 15 and 16 instead which resolves
the error.  Do you think that is an acceptable solution?

I think the only difference is that timers 15 and 16 are in l4_per3 instead
of l4_per1. I doubt that matters as they are pretty much always clocked in
this case. If you want to check you can run cyclictest :)

If so, I will post the patch to the list.

OK thanks,

Tony

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