From patchwork Thu Apr 29 07:45:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 12230617 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01B04C433B4 for ; Thu, 29 Apr 2021 07:45:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B775F61424 for ; Thu, 29 Apr 2021 07:45:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239295AbhD2Hq0 (ORCPT ); Thu, 29 Apr 2021 03:46:26 -0400 Received: from muru.com ([72.249.23.125]:49792 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238725AbhD2HqZ (ORCPT ); Thu, 29 Apr 2021 03:46:25 -0400 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 0A3BF804D; Thu, 29 Apr 2021 07:45:38 +0000 (UTC) From: Tony Lindgren To: linux-omap@vger.kernel.org Cc: Dave Gerlach , Faiz Abbas , Greg Kroah-Hartman , Grygorii Strashko , Keerthy , Nishanth Menon , Suman Anna , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] bus: ti-sysc: Fix am335x resume hang for usb otg module Date: Thu, 29 Apr 2021 10:45:33 +0300 Message-Id: <20210429074533.33355-1-tony@atomide.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org On am335x, suspend and resume only works once, and the system hangs if suspend is attempted again. However, turns out suspend and resume works fine multiple times if the USB OTG driver for musb controller is loaded. The issue is caused my the interconnect target module losing context during suspend, and it needs a restore on resume to be reconfigure again as debugged earlier by Dave Gerlach . There are also other modules that need a restore on resume, like gpmc as noted by Dave. So let's add a common way to restore an interconnect target module based on a quirk flag. For now, let's enable the quirk for am335x otg only to fix the suspend and resume issue. As gpmc is not causing hangs based on tests with BeagleBone, let's patch gpmc separately. For gpmc, we also need a hardware reset done before restore according to Dave. To reinit the modules, we decouple system suspend from PM runtime. We replace calls to pm_runtime_force_suspend() and pm_runtime_force_resume() with direct calls to internal functions and rely on the driver internal state. There no point trying to handle complex system suspend and resume quirks via PM runtime. This is issue should have already been noticed with commit 1819ef2e2d12 ("bus: ti-sysc: Use swsup quirks also for am335x musb") when quirk handling was added for am335x otg for swsup. But the issue went unnoticed as having musb driver loaded hides the issue, and suspend and resume works once without the driver loaded. Fixes: 1819ef2e2d12 ("bus: ti-sysc: Use swsup quirks also for am335x musb") Suggested-by: Dave Gerlach Signed-off-by: Tony Lindgren --- drivers/bus/ti-sysc.c | 29 ++++++++++++++++++++++++--- include/linux/platform_data/ti-sysc.h | 1 + 2 files changed, 27 insertions(+), 3 deletions(-) diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -1295,12 +1295,18 @@ static int __maybe_unused sysc_noirq_suspend(struct device *dev) (SYSC_QUIRK_LEGACY_IDLE | SYSC_QUIRK_NO_IDLE)) return 0; - return pm_runtime_force_suspend(dev); + if (!ddata->enabled) + return 0; + + ddata->needs_resume = 1; + + return sysc_runtime_suspend(dev); } static int __maybe_unused sysc_noirq_resume(struct device *dev) { struct sysc *ddata; + int error; ddata = dev_get_drvdata(dev); @@ -1308,7 +1314,23 @@ static int __maybe_unused sysc_noirq_resume(struct device *dev) (SYSC_QUIRK_LEGACY_IDLE | SYSC_QUIRK_NO_IDLE)) return 0; - return pm_runtime_force_resume(dev); + /* Only enable module if it was on, or needs to be reinitialized */ + if (ddata->needs_resume || + ddata->cfg.quirks & SYSC_QUIRK_REINIT_ON_RESUME) { + error = sysc_runtime_resume(dev); + if (error) + dev_warn(dev, "noirq_resume failed: %i\n", error); + } + + /* Idle quirky module again if it was not on before suspend */ + if (ddata->cfg.quirks & SYSC_QUIRK_REINIT_ON_RESUME && + !ddata->needs_resume) { + error = sysc_runtime_suspend(dev); + } + + ddata->needs_resume = 0; + + return error; } static const struct dev_pm_ops sysc_pm_ops = { @@ -1417,7 +1439,8 @@ static const struct sysc_revision_quirk sysc_revision_quirks[] = { SYSC_QUIRK("usb_otg_hs", 0, 0x400, 0x404, 0x408, 0x00000050, 0xffffffff, SYSC_QUIRK_SWSUP_SIDLE | SYSC_QUIRK_SWSUP_MSTANDBY), SYSC_QUIRK("usb_otg_hs", 0, 0, 0x10, -ENODEV, 0x4ea2080d, 0xffffffff, - SYSC_QUIRK_SWSUP_SIDLE | SYSC_QUIRK_SWSUP_MSTANDBY), + SYSC_QUIRK_SWSUP_SIDLE | SYSC_QUIRK_SWSUP_MSTANDBY | + SYSC_QUIRK_REINIT_ON_RESUME), SYSC_QUIRK("wdt", 0, 0, 0x10, 0x14, 0x502a0500, 0xfffff0f0, SYSC_MODULE_QUIRK_WDT), /* PRUSS on am3, am4 and am5 */ diff --git a/include/linux/platform_data/ti-sysc.h b/include/linux/platform_data/ti-sysc.h --- a/include/linux/platform_data/ti-sysc.h +++ b/include/linux/platform_data/ti-sysc.h @@ -50,6 +50,7 @@ struct sysc_regbits { s8 emufree_shift; }; +#define SYSC_QUIRK_REINIT_ON_RESUME BIT(27) #define SYSC_QUIRK_GPMC_DEBUG BIT(26) #define SYSC_MODULE_QUIRK_ENA_RESETDONE BIT(25) #define SYSC_MODULE_QUIRK_PRUSS BIT(24)