From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967278AbeAONWN (ORCPT + 1 other); Mon, 15 Jan 2018 08:22:13 -0500 Received: from mail-qk0-f195.google.com ([209.85.220.195]:33576 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966749AbeAONWK (ORCPT ); Mon, 15 Jan 2018 08:22:10 -0500 X-Google-Smtp-Source: ACJfBou09h0dx5jXGlwJyzFQwwvZpOzRqlorLNOe5KGRt1OcIVBXCPgiK2+OJgpQRMKtu1PnJYlZiXocvM7bPMhZxKU= MIME-Version: 1.0 In-Reply-To: References: <4928977.5hd79RbQlp@aspire.rjw.lan> <12351114.Ym7QOfxZhK@aspire.rjw.lan> From: Geert Uytterhoeven Date: Mon, 15 Jan 2018 14:22:08 +0100 X-Google-Sender-Auth: PNWKY9LBkKSakn7eSNEzRHvlb0s Message-ID: Subject: Re: [PATCH 0/2] PM / core: genpd fix and pm_runtime_force_suspend|resume() rework To: "Rafael J. Wysocki" Cc: "Rafael J. Wysocki" , Linux PM , Ulf Hansson , LKML , Linux-Renesas Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Hi Rafael, On Mon, Jan 15, 2018 at 9:16 AM, Geert Uytterhoeven wrote: > On Mon, Jan 15, 2018 at 1:04 AM, Rafael J. Wysocki wrote: >> On Sun, Jan 14, 2018 at 10:48 AM, Geert Uytterhoeven >> wrote: >>> On Sat, Jan 13, 2018 at 1:38 AM, Rafael J. Wysocki wrote: >>>> On Friday, January 12, 2018 3:31:09 PM CET Geert Uytterhoeven wrote: >>>>> On Fri, Jan 12, 2018 at 2:00 PM, Rafael J. Wysocki wrote: >>>>> > This comes from the recent discussion/testing effort that ensued after my >>>>> > pm_runtime_force_suspend|resume() changes proposal: >>>>> > >>>>> > https://marc.info/?t=151497772000004&r=1&w=2 >>>>> > >>>>> > Patch [1/2] basically is https://patchwork.kernel.org/patch/10152873/ rebased >>>>> > on top of the current linux-next branch of the linux-pm.git tree (the relevant >>>>> > part should be there in the linux-next tree proper ATM). It applies on top >>>>> > of https://patchwork.kernel.org/patch/10156077/ which should apply to the Linus' >>>>> > tree cleanly. >>>>> > >>>>> > Patch [2/2] is a resend of https://patchwork.kernel.org/patch/10142047/ with >>>>> > a very minor changelog modification and the R-b tag from Ulf. >>>>> > >>>>> > Geert, if possible, please test this on the Renesas systems that had the >>>>> > problem with https://patchwork.kernel.org/patch/10142047/ previously and let >>>>> > me know if you still see issues. >>>>> >>>>> I've tested this on two very similar systems: Salvator-XS with R-Car H3 ES2.0, >>>>> and Salvator-X with R-Car M3-W ES1.0. >>>>> >>>>> On the M3-based system, everything seems to work fine. >>>> >>>> Good. >>>> >>>>> On the H3-based system, the serial console (the /dev/ttySC0 device, not kernel >>>>> serial output) is dead after resume from s2ram, with and without >>>>> no_console_suspend. >>>>> >>>>> With no_console_suspend, I see: >>>>> >>>>> ttySC ttySC0: 1 input overrun(s) >>>>> >>>>> after typing on the serial console, so it looks like an interrupt problem. >>>>> >>>>> This issue seems to be caused by patch [1/2]. But I have no idea what's >>>>> really happening, and why the two systems behave differently. >>> >>> Could be a firmware issue, too. >>> While the kernel images are identical, the ARM trusted firmware configs aren't >>> (same version, though). >>> >>> I'll do some more investigation... >> >> OK, thanks! >> >> It also would be good to know the topology of the device hierarchy and >> how that maps to the domains on the failing system (and which UART >> clocks are operated by genpd). > > The topology is the same on both systems. I did miss a small difference in topology: in pm/linux-next, H3 has DMA enabled for SCIF2, while M3 hasn't (yet). With DMA enabled on M3, it fails in the same way. As genpd_resume_noirq() no longer calls pm_runtime_force_resume(), rcar_dmac_runtime_resume() is no longer called, and the DMAC's registers are no longer reinitialized after system resume, breaking the serial port. 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