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: linux-renesas-soc-ow...@vger.kernel.org <linux-renesas-soc- > ow...@vger.kernel.org> On Behalf Of Geert Uytterhoeven > Sent: 24 January 2019 10:16 > To: Biju Das <biju....@bp.renesas.com> > Cc: Rob Herring <robh...@kernel.org>; Mark Rutland > <mark.rutl...@arm.com>; Simon Horman <ho...@verge.net.au>; Magnus > Damm <magnus.d...@gmail.com>; Linux-Renesas <linux-renesas- > s...@vger.kernel.org>; open list:OPEN FIRMWARE AND FLATTENED DEVICE > TREE BINDINGS <devicet...@vger.kernel.org>; Geert Uytterhoeven > <geert+rene...@glider.be>; Chris Paterson > <chris.paters...@renesas.com>; Daniel Lezcano > <daniel.lezc...@linaro.org>; Thomas Gleixner <t...@linutronix.de>; John > Stultz <john.stu...@linaro.org>; Fabrizio Castro > <fabrizio.cas...@bp.renesas.com>; Samuel Holland <sam...@sholland.org> > Subject: Re: [PATCH] arm64: dts: renesas: r8a7796: Add CMT device nodes > > Hi Biju, > > On Fri, Oct 26, 2018 at 10:32 AM Biju Das <biju....@bp.renesas.com> wrote: > > This patch adds CMT{0|1|2|3} device nodes for r8a7796 SoC. > > > > Signed-off-by: Biju Das <biju....@bp.renesas.com> > > --- > > 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- > sam...@sholland.org/ > > 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 Renesas Electronics Europe Ltd, Dukes Meadow, Millboard Road, Bourne End, Buckinghamshire, SL8 5FH, UK. Registered in England & Wales under Registered No. 04586709.