From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752232AbbASJpc (ORCPT ); Mon, 19 Jan 2015 04:45:32 -0500 Received: from mail-ie0-f175.google.com ([209.85.223.175]:65439 "EHLO mail-ie0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751726AbbASJpa (ORCPT ); Mon, 19 Jan 2015 04:45:30 -0500 Date: Mon, 19 Jan 2015 09:45:25 +0000 From: Lee Jones To: Roger Tseng Cc: Samuel Ortiz , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, driverdev-devel@linuxdriverproject.org, wei_wang@realsil.com.cn, micky_ching@realsil.com.cn Subject: Re: [PATCH 1/2] mfd: rtsx_usb: Fix runtime PM deadlock Message-ID: <20150119094525.GK21886@x1> References: <1421306085-32254-1-git-send-email-rogerable@realtek.com> <1421306085-32254-2-git-send-email-rogerable@realtek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1421306085-32254-2-git-send-email-rogerable@realtek.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 15 Jan 2015, Roger Tseng wrote: > sd_set_power_mode() in derived module drivers/mmc/host/rtsx_usb_sdmmc.c > acquires dev_mutex and then calls pm_runtime_get_sync() to make sure the > device is awake while initializing a newly inserted card. Once it is > called during suspending state and explicitly before rtsx_usb_suspend() > acquires the same dev_mutex, both routine deadlock and further hang the > driver because pm_runtime_get_sync() waits the pending PM operations. > > Fix this by using an empty suspend method. mmc_core always turns the > LED off after a request is done and thus it is ok to remove the only > rtsx_usb_turn_off_led() here. > > Cc: # v3.16+ > Fixes: 730876be2566 ("mfd: Add realtek USB card reader driver") > Signed-off-by: Roger Tseng > --- > drivers/mfd/rtsx_usb.c | 9 --------- > 1 file changed, 9 deletions(-) Applied, thanks. > diff --git a/drivers/mfd/rtsx_usb.c b/drivers/mfd/rtsx_usb.c > index dbdd0faeb6ce..076694126e5d 100644 > --- a/drivers/mfd/rtsx_usb.c > +++ b/drivers/mfd/rtsx_usb.c > @@ -687,15 +687,6 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message) > dev_dbg(&intf->dev, "%s called with pm message 0x%04x\n", > __func__, message.event); > > - /* > - * Call to make sure LED is off during suspend to save more power. > - * It is NOT a permanent state and could be turned on anytime later. > - * Thus no need to call turn_on when resunming. > - */ > - mutex_lock(&ucr->dev_mutex); > - rtsx_usb_turn_off_led(ucr); > - mutex_unlock(&ucr->dev_mutex); > - > return 0; > } > -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog