From patchwork Wed Sep 19 14:33:27 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "stern@rowland.harvard.edu" X-Patchwork-Id: 1477831 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id B1B6C3FE65 for ; Wed, 19 Sep 2012 14:33:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751693Ab2ISOd3 (ORCPT ); Wed, 19 Sep 2012 10:33:29 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:35331 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751790Ab2ISOd2 (ORCPT ); Wed, 19 Sep 2012 10:33:28 -0400 Received: (qmail 2556 invoked by uid 2102); 19 Sep 2012 10:33:27 -0400 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 19 Sep 2012 10:33:27 -0400 Date: Wed, 19 Sep 2012 10:33:27 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: "Rafael J. Wysocki" cc: Linux-pm mailing list Subject: [PATCH] PM: Prevent runtime suspend during system resume Message-ID: MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org This patch (as1591) moves the pm_runtime_get_noresume() and pm_runtime_put_sync() calls from __device_suspend() and device_resume() to device_prepare() and device_complete() in the PM core. The reason for doing this is to make sure that parent devices remain at full power (i.e., don't go into runtime suspend) while their children are being resumed from a system sleep. The PCI core already contained equivalent code to serve the same purpose. The patch removes the duplicated code, since it is no longer needed. One of the comments from the PCI core gets moved into the PM core, and a second comment is added to explain whe the _get_noresume and _put_sync calls are present. Signed-off-by: Alan Stern --- We discussed this some time ago, but I lost track of the patch. Here it is, at last. drivers/base/power/main.c | 29 ++++++++++++++++++----------- drivers/pci/pci-driver.c | 17 ----------------- 2 files changed, 18 insertions(+), 28 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: usb-3.6/drivers/base/power/main.c =================================================================== --- usb-3.6.orig/drivers/base/power/main.c +++ usb-3.6/drivers/base/power/main.c @@ -565,7 +565,6 @@ static int device_resume(struct device * pm_callback_t callback = NULL; char *info = NULL; int error = 0; - bool put = false; TRACE_DEVICE(dev); TRACE_RESUME(0); @@ -583,7 +582,6 @@ static int device_resume(struct device * goto Unlock; pm_runtime_enable(dev); - put = true; if (dev->pm_domain) { info = "power domain "; @@ -636,9 +634,6 @@ static int device_resume(struct device * TRACE_RESUME(error); - if (put) - pm_runtime_put_sync(dev); - return error; } @@ -749,6 +744,8 @@ static void device_complete(struct devic } device_unlock(dev); + + pm_runtime_put_sync(dev); } /** @@ -1043,12 +1040,16 @@ static int __device_suspend(struct devic if (async_error) goto Complete; - pm_runtime_get_noresume(dev); + /* + * If a device configured to wake up the system from sleep states + * has been suspended at run time and there's a resume request pending + * for it, this is equivalent to the device signaling wakeup, so the + * system suspend operation should be aborted. + */ if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) pm_wakeup_event(dev, 0); if (pm_wakeup_pending()) { - pm_runtime_put_sync(dev); async_error = -EBUSY; goto Complete; } @@ -1111,12 +1112,10 @@ static int __device_suspend(struct devic Complete: complete_all(&dev->power.completion); - if (error) { - pm_runtime_put_sync(dev); + if (error) async_error = error; - } else if (dev->power.is_suspended) { + else if (dev->power.is_suspended) __pm_runtime_disable(dev, false); - } return error; } @@ -1209,6 +1208,14 @@ static int device_prepare(struct device char *info = NULL; int error = 0; + /* + * If a device's parent goes into runtime suspend at the wrong time, + * it won't be possible to resume the device. To prevent this we + * block runtime suspend here, during the prepare phase, and allow + * it again during the complete phase. + */ + pm_runtime_get_noresume(dev); + device_lock(dev); dev->power.wakeup_path = device_may_wakeup(dev); Index: usb-3.6/drivers/pci/pci-driver.c =================================================================== --- usb-3.6.orig/drivers/pci/pci-driver.c +++ usb-3.6/drivers/pci/pci-driver.c @@ -624,21 +624,6 @@ static int pci_pm_prepare(struct device int error = 0; /* - * If a PCI device configured to wake up the system from sleep states - * has been suspended at run time and there's a resume request pending - * for it, this is equivalent to the device signaling wakeup, so the - * system suspend operation should be aborted. - */ - pm_runtime_get_noresume(dev); - if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) - pm_wakeup_event(dev, 0); - - if (pm_wakeup_pending()) { - pm_runtime_put_sync(dev); - return -EBUSY; - } - - /* * PCI devices suspended at run time need to be resumed at this * point, because in general it is necessary to reconfigure them for * system suspend. Namely, if the device is supposed to wake up the @@ -661,8 +646,6 @@ static void pci_pm_complete(struct devic if (drv && drv->pm && drv->pm->complete) drv->pm->complete(dev); - - pm_runtime_put_sync(dev); } #else /* !CONFIG_PM_SLEEP */