Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751173AbaDPBfV (ORCPT ); Tue, 15 Apr 2014 21:35:21 -0400 Received: from rtits2.realtek.com ([60.250.210.242]:45585 "EHLO rtits2.realtek.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750919AbaDPBfU (ORCPT ); Tue, 15 Apr 2014 21:35:20 -0400 X-SpamFilter-By: BOX Solutions SpamTrap 5.39 with qID s3G1YkLA002303, This message is accepted by code: ctloc85258 From: To: , CC: , , , , , , , , Micky Ching Subject: [PATCH] mmc: rtsx: fix possible circular locking dependency Date: Wed, 16 Apr 2014 09:38:44 +0800 Message-ID: <1397612325-4968-1-git-send-email-micky_ching@realsil.com.cn> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [172.29.41.103] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Micky Ching To avoid dead lock, we need make sure host->lock is always acquire before pcr->lock. But in irq handler, we acquired pcr->lock in rtsx mfd driver, and sd_isr_done_transfer() is called during pcr->lock already acquired. Since in sd_isr_done_transfer() the only work we do is schdule tasklet, the cmd_tasklet and data_tasklet never conflict, so it is safe to remove spin_lock() here. Signed-off-by: Micky Ching --- drivers/mmc/host/rtsx_pci_sdmmc.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c index 453e1d4..40695e0 100644 --- a/drivers/mmc/host/rtsx_pci_sdmmc.c +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c @@ -108,12 +108,10 @@ static void sd_isr_done_transfer(struct platform_device *pdev) { struct realtek_pci_sdmmc *host = platform_get_drvdata(pdev); - spin_lock(&host->lock); if (host->cmd) tasklet_schedule(&host->cmd_tasklet); - if (host->data) + else if (host->data) tasklet_schedule(&host->data_tasklet); - spin_unlock(&host->lock); } static void sd_request_timeout(unsigned long host_addr) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/