From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752768AbbADPTI (ORCPT ); Sun, 4 Jan 2015 10:19:08 -0500 Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]:57966 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752648AbbADPTB (ORCPT ); Sun, 4 Jan 2015 10:19:01 -0500 From: Jisheng Zhang To: , CC: , , , , Jisheng Zhang , Subject: [PATCH next 1/2] mmc: sdhci-pxav3: fix unbalanced clock issues during probe Date: Sun, 4 Jan 2015 23:15:47 +0800 Message-ID: <1420384548-7816-2-git-send-email-jszhang@marvell.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1420384548-7816-1-git-send-email-jszhang@marvell.com> References: <1420384548-7816-1-git-send-email-jszhang@marvell.com> MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.13.68,1.0.33,0.0.0000 definitions=2015-01-04_03:2015-01-02,2015-01-04,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1402240000 definitions=main-1501040160 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: # v3.11+ --- 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 ca3424e..1255dd2 100644 --- a/drivers/mmc/host/sdhci-pxav3.c +++ b/drivers/mmc/host/sdhci-pxav3.c @@ -365,10 +365,11 @@ 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); @@ -391,8 +392,8 @@ 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: -- 2.1.4