Hi Geert,
Thanks for the feedback. I started testing CMT on latest
kernel(Linux-next-20190125 and also renesas-dev) and found that it is broken on
R-Car M3-W device.
On further investigation the patch (" 8234f6734c5d74ac794e5517437f51c57d65f865"
PM-runtime: Switch autosuspend over to using hrtimers) is causing the issue.
During clock source switching, It calls the function "sh_cmt_enable" which
calls " pm_runtime_get_sync(&ch->cmt->pdev->dev);" and after that console
freezes.
Sergei: Have you noticed this issue on R-Car V3M and V3H boards with latest
kernel?
Regards,
Biju
> -----Original Message-----
> From: [email protected] <linux-renesas-soc-
> [email protected]> On Behalf Of Geert Uytterhoeven
> Sent: 24 January 2019 10:16
> To: Biju Das <[email protected]>
> Cc: Rob Herring <[email protected]>; Mark Rutland
> <[email protected]>; Simon Horman <[email protected]>; Magnus
> Damm <[email protected]>; Linux-Renesas <linux-renesas-
> [email protected]>; open list:OPEN FIRMWARE AND FLATTENED DEVICE
> TREE BINDINGS <[email protected]>; Geert Uytterhoeven
> <[email protected]>; Chris Paterson
> <[email protected]>; Daniel Lezcano
> <[email protected]>; Thomas Gleixner <[email protected]>; John
> Stultz <[email protected]>; Fabrizio Castro
> <[email protected]>; Samuel Holland <[email protected]>
> Subject: Re: [PATCH] arm64: dts: renesas: r8a7796: Add CMT device nodes
>
> Hi Biju,
>
> On Fri, Oct 26, 2018 at 10:32 AM Biju Das <[email protected]> wrote:
> > This patch adds CMT{0|1|2|3} device nodes for r8a7796 SoC.
> >
> > Signed-off-by: Biju Das <[email protected]>
> > ---
> > This patch is tested against renesas-dev
> >
> > I have executed on inconsistency-check, nanosleep and
> > clocksource_switch selftests on this arm64 SoC. The
> > inconsistency-check and nanosleep tests are working fine.The
> > clocksource_switch asynchronous test is failing due to inconsistency-check
> failure on "arch_sys_counter".
> >
> > But if i skip the clocksource_switching of "arch_sys_counter", the
> > asynchronous test is passing for CMT0/1/2/3 timer.
> >
> > Has any one noticed this issue?
>
> clockevents/next now has commit 7cd6dca3600d8d71
> ("clocksource/drivers/arch_timer: Workaround for Allwinner A64 timer
> instability"). Perhaps this is related, and the same test program may
> indicate
> similar issues?
>
> See also https://lore.kernel.org/lkml/20190113021719.46457-2-
> [email protected]/
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like
> that.
> -- Linus Torvalds
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