From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755925AbbCFLC7 (ORCPT ); Fri, 6 Mar 2015 06:02:59 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:44043 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932216AbbCFJ6d (ORCPT ); Fri, 6 Mar 2015 04:58:33 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Jisheng Zhang , Ulf Hansson , Luis Henriques Subject: [PATCH 3.16.y-ckt 030/183] mmc: sdhci-pxav3: fix unbalanced clock issues during probe Date: Fri, 6 Mar 2015 09:55:21 +0000 Message-Id: <1425635874-19087-31-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1425635874-19087-1-git-send-email-luis.henriques@canonical.com> References: <1425635874-19087-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt8 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Jisheng Zhang commit 62cf983ad84275f8580c807e5e596216c46773cf upstream. Commit 0dcaa2499b7d ("sdhci-pxav3: Fix runtime PM initialization") tries to fix one hang issue caused by calling sdhci_add_host() on a suspended device. The fix enables the clock twice, once by clk_prepare_enable() and another by pm_runtime_get_sync(), meaning that the clock will never be gated at runtime PM suspend. I observed the power consumption regression on Marvell BG2Q SoCs. In fact, the fix is not correct. There still be a very small window during which a runtime suspend might somehow occur after pm_runtime_enable() but before pm_runtime_get_sync(). This patch fixes all of the two problems by just incrementing the usage counter before pm_runtime_enable(). It also adjust the order of disabling runtime pm and storing the usage count in the error path to handle clock gating properly. Signed-off-by: Jisheng Zhang Signed-off-by: Ulf Hansson Signed-off-by: Luis Henriques --- drivers/mmc/host/sdhci-pxav3.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c index bdfdf5273252..81143e57b2ff 100644 --- a/drivers/mmc/host/sdhci-pxav3.c +++ b/drivers/mmc/host/sdhci-pxav3.c @@ -356,10 +356,11 @@ static int sdhci_pxav3_probe(struct platform_device *pdev) } } - pm_runtime_enable(&pdev->dev); - pm_runtime_get_sync(&pdev->dev); + pm_runtime_get_noresume(&pdev->dev); + pm_runtime_set_active(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, PXAV3_RPM_DELAY_MS); pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_enable(&pdev->dev); pm_suspend_ignore_children(&pdev->dev, 1); ret = sdhci_add_host(host); @@ -382,8 +383,8 @@ static int sdhci_pxav3_probe(struct platform_device *pdev) return 0; err_add_host: - pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); + pm_runtime_put_noidle(&pdev->dev); err_of_parse: err_cd_req: err_mbus_win: