From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85324C433EF for ; Wed, 23 Feb 2022 13:48:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235380AbiBWNtW (ORCPT ); Wed, 23 Feb 2022 08:49:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232897AbiBWNtV (ORCPT ); Wed, 23 Feb 2022 08:49:21 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1AD08AF1E2 for ; Wed, 23 Feb 2022 05:48:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1645624133; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=QKY99ZXZ9YfHFSEaY8xlB4C3QXeafgWGGiJQpFtDBaA=; b=hUmQFjwMhOSkE8NSalE9UHEBixTSvOo+YYmjCW3DaXHaWVbImJ1/gddDPJbicvWfAaomv/ 6UaEULVWOsyRoT2ELpUQ/d89aoA5SJDg1c1ZG4U9aieA22slVCUNVJ4hvdALjegYKPjhrv 6Odnw/o4H/hsW69qA1cn9C6KzZ4lXjg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-669-g2DAv-W9OYmqtv89seDoCg-1; Wed, 23 Feb 2022 08:48:50 -0500 X-MC-Unique: g2DAv-W9OYmqtv89seDoCg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AE4D2185A0C0; Wed, 23 Feb 2022 13:48:48 +0000 (UTC) Received: from localhost.localdomain (unknown [10.39.195.37]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5F86F838DB; Wed, 23 Feb 2022 13:48:47 +0000 (UTC) From: Hans de Goede To: Jarkko Nikula , Wolfram Sang , Andy Shevchenko , Mika Westerberg Cc: Hans de Goede , linux-i2c@vger.kernel.org Subject: [PATCH 1/2] i2c: designware: Lock the adapter while setting the suspended flag Date: Wed, 23 Feb 2022 14:48:38 +0100 Message-Id: <20220223134839.731138-1-hdegoede@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Lock the adapter while setting the suspended flag, to ensure that other locked code always sees the change immediately, rather then possibly using a stale value. This involves splitting the suspend/resume callbacks into separate runtime and normal suspend/resume calls. This is necessary because i2c_dw_xfer() will get called by the i2c-core with the adapter locked and it in turn calls the runtime-resume callback through pm_runtime_get_sync(). So the runtime versions of the suspend/resume callbacks cannot take the adapter-lock. Note this patch simply makes the runtime suspend/resume callbacks not deal with the suspended flag at all. During runtime the pm_runtime_get_sync() from i2c_dw_xfer() will always ensure that the adapter is resumed when necessary. The suspended flag check is only necessary to check proper suspend/resume ordering during normal suspend/resume which makes the pm_runtime_get_sync() call a no-op. Signed-off-by: Hans de Goede --- drivers/i2c/busses/i2c-designware-pcidrv.c | 31 +++++++++++++++++---- drivers/i2c/busses/i2c-designware-platdrv.c | 31 +++++++++++++++++---- 2 files changed, 52 insertions(+), 10 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c index ef4250f8852b..9553d7075223 100644 --- a/drivers/i2c/busses/i2c-designware-pcidrv.c +++ b/drivers/i2c/busses/i2c-designware-pcidrv.c @@ -213,14 +213,30 @@ static struct dw_pci_controller dw_pci_controllers[] = { }, }; +static int __maybe_unused i2c_dw_pci_runtime_suspend(struct device *dev) +{ + struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); + + i_dev->disable(i_dev); + return 0; +} + static int __maybe_unused i2c_dw_pci_suspend(struct device *dev) { struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); + i2c_lock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER); i_dev->suspended = true; - i_dev->disable(i_dev); + i2c_unlock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER); - return 0; + return i2c_dw_pci_runtime_suspend(dev); +} + +static int __maybe_unused i2c_dw_pci_runtime_resume(struct device *dev) +{ + struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); + + return i_dev->init(i_dev); } static int __maybe_unused i2c_dw_pci_resume(struct device *dev) @@ -228,14 +244,19 @@ static int __maybe_unused i2c_dw_pci_resume(struct device *dev) struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); int ret; - ret = i_dev->init(i_dev); + ret = i2c_dw_pci_runtime_resume(dev); + + i2c_lock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER); i_dev->suspended = false; + i2c_unlock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER); return ret; } -static UNIVERSAL_DEV_PM_OPS(i2c_dw_pm_ops, i2c_dw_pci_suspend, - i2c_dw_pci_resume, NULL); +static const struct dev_pm_ops i2c_dw_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(i2c_dw_pci_suspend, i2c_dw_pci_resume) + SET_RUNTIME_PM_OPS(i2c_dw_pci_runtime_suspend, i2c_dw_pci_runtime_resume, NULL) +}; static int i2c_dw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 2bd81abc86f6..8e45f65bab73 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -368,12 +368,10 @@ static void dw_i2c_plat_complete(struct device *dev) #endif #ifdef CONFIG_PM -static int dw_i2c_plat_suspend(struct device *dev) +static int dw_i2c_plat_runtime_suspend(struct device *dev) { struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); - i_dev->suspended = true; - if (i_dev->shared_with_punit) return 0; @@ -383,7 +381,18 @@ static int dw_i2c_plat_suspend(struct device *dev) return 0; } -static int dw_i2c_plat_resume(struct device *dev) +static int dw_i2c_plat_suspend(struct device *dev) +{ + struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); + + i2c_lock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER); + i_dev->suspended = true; + i2c_unlock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER); + + return dw_i2c_plat_runtime_suspend(dev); +} + +static int dw_i2c_plat_runtime_resume(struct device *dev) { struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); @@ -391,7 +400,19 @@ static int dw_i2c_plat_resume(struct device *dev) i2c_dw_prepare_clk(i_dev, true); i_dev->init(i_dev); + + return 0; +} + +static int dw_i2c_plat_resume(struct device *dev) +{ + struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); + + dw_i2c_plat_runtime_resume(dev); + + i2c_lock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER); i_dev->suspended = false; + i2c_unlock_bus(&i_dev->adapter, I2C_LOCK_ROOT_ADAPTER); return 0; } @@ -400,7 +421,7 @@ static const struct dev_pm_ops dw_i2c_dev_pm_ops = { .prepare = dw_i2c_plat_prepare, .complete = dw_i2c_plat_complete, SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) - SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) + SET_RUNTIME_PM_OPS(dw_i2c_plat_runtime_suspend, dw_i2c_plat_runtime_resume, NULL) }; #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) -- 2.35.1