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 X-Spam-Level: X-Spam-Status: No, score=-10.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 4FA91C43387 for ; Fri, 11 Jan 2019 14:50:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1AC48206B6 for ; Fri, 11 Jan 2019 14:50:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547218256; bh=SU5bnpz0LvnY+oE6LGN/UxvhAFIJ5xtDJ6Z4EkU3FqY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Q+pjiUl3+mbf8TgojsPj2GHb4uPpnroNZap+UHXunWBYy2bYejr9rHMLgzFLrmlEX 7si81mbhyixnk663rAYX97PWyXHUCYpWfaWyFlhl5voQcT8DXpKTcr9VyLRG0HpFgq WqCC7m1SnFhqujYjSBEmigQVN9+XLPFCI6nnMwVE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391659AbfAKOuy (ORCPT ); Fri, 11 Jan 2019 09:50:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:60854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391140AbfAKOkA (ORCPT ); Fri, 11 Jan 2019 09:40:00 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2BADC206B6; Fri, 11 Jan 2019 14:39:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547217599; bh=SU5bnpz0LvnY+oE6LGN/UxvhAFIJ5xtDJ6Z4EkU3FqY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=s8YkaEr0GoPl38ZAWYxsy5s3U5+M1gZBVK4eniAb7hET5GrLtrqz92or4ujTqdGqb o6tp1JNTPvVKA9ZLy1d5YFs1d7I/MdqK4b4loXfbDkiABTr9Tpvg+kIDS7+kgy3Fe5 +1+/vGSSUqhWubTjoDw7XIs3PfyzOol9/0h8xgjk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mika Westerberg , Jarkko Nikula , Bjorn Helgaas , Jean Delvare , "Rafael J. Wysocki" Subject: [PATCH 4.19 122/148] PCI / PM: Allow runtime PM without callback functions Date: Fri, 11 Jan 2019 15:15:00 +0100 Message-Id: <20190111131119.129293070@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190111131114.337122649@linuxfoundation.org> References: <20190111131114.337122649@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jarkko Nikula commit c5eb1190074cfb14c5d9cac692f1912eecf1a5e4 upstream. a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM") nullified the runtime PM suspend/resume callback pointers while keeping the runtime PM enabled. This caused the SMBus PCI device to stay in D0 with /sys/devices/.../power/runtime_status showing "error" when the runtime PM framework attempted to autosuspend the device. This is due to PCI bus runtime PM, which checks for driver runtime PM callbacks and returns -ENOSYS if they are not set. Since i2c-i801.c doesn't need to do anything device-specific for runtime PM, Jean Delvare proposed this be fixed in the PCI core rather than adding dummy runtime PM callback functions in the PCI drivers. Change pci_pm_runtime_suspend()/pci_pm_runtime_resume() so they allow changing the PCI device power state during runtime PM transitions even if the driver supplies no runtime PM callbacks. This fixes the runtime PM regression on i2c-i801.c. It is not obvious why the code previously required the runtime PM callbacks. The test has been there since the code was introduced by 6cbf82148ff2 ("PCI PM: Run-time callbacks for PCI bus type"). On the other hand, a similar change was done to generic runtime PM callbacks in 05aa55dddb9e ("PM / Runtime: Lenient generic runtime pm callbacks"). Fixes: a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM") Reported-by: Mika Westerberg Signed-off-by: Jarkko Nikula Signed-off-by: Bjorn Helgaas Reviewed-by: Jean Delvare Reviewed-by: Rafael J. Wysocki Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci-driver.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1251,30 +1251,29 @@ static int pci_pm_runtime_suspend(struct return 0; } - if (!pm || !pm->runtime_suspend) - return -ENOSYS; - pci_dev->state_saved = false; - error = pm->runtime_suspend(dev); - if (error) { + if (pm && pm->runtime_suspend) { + error = pm->runtime_suspend(dev); /* * -EBUSY and -EAGAIN is used to request the runtime PM core * to schedule a new suspend, so log the event only with debug * log level. */ - if (error == -EBUSY || error == -EAGAIN) + if (error == -EBUSY || error == -EAGAIN) { dev_dbg(dev, "can't suspend now (%pf returned %d)\n", pm->runtime_suspend, error); - else + return error; + } else if (error) { dev_err(dev, "can't suspend (%pf returned %d)\n", pm->runtime_suspend, error); - - return error; + return error; + } } pci_fixup_device(pci_fixup_suspend, pci_dev); - if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0 + if (pm && pm->runtime_suspend + && !pci_dev->state_saved && pci_dev->current_state != PCI_D0 && pci_dev->current_state != PCI_UNKNOWN) { WARN_ONCE(pci_dev->current_state != prev, "PCI PM: State of device not saved by %pF\n", @@ -1292,7 +1291,7 @@ static int pci_pm_runtime_suspend(struct static int pci_pm_runtime_resume(struct device *dev) { - int rc; + int rc = 0; struct pci_dev *pci_dev = to_pci_dev(dev); const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; @@ -1306,14 +1305,12 @@ static int pci_pm_runtime_resume(struct if (!pci_dev->driver) return 0; - if (!pm || !pm->runtime_resume) - return -ENOSYS; - pci_fixup_device(pci_fixup_resume_early, pci_dev); pci_enable_wake(pci_dev, PCI_D0, false); pci_fixup_device(pci_fixup_resume, pci_dev); - rc = pm->runtime_resume(dev); + if (pm && pm->runtime_resume) + rc = pm->runtime_resume(dev); pci_dev->runtime_d3cold = false;