Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752628AbcCJPiG (ORCPT ); Thu, 10 Mar 2016 10:38:06 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:51369 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752799AbcCJPhk (ORCPT ); Thu, 10 Mar 2016 10:37:40 -0500 From: Yaniv Gardi To: James.Bottomley@HansenPartnership.com Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-arm-msm@vger.kernel.org, santoshsy@gmail.com, linux-scsi-owner@vger.kernel.org, ygardi@codeaurora.org, Subhash Jadavani , Vinayak Holikatti , "James E.J. Bottomley" , "Martin K. Petersen" Subject: [PATCH v8 02/17] scsi: ufs: avoid spurious UFS host controller interrupts Date: Thu, 10 Mar 2016 17:37:06 +0200 Message-Id: <1457624241-20525-3-git-send-email-ygardi@codeaurora.org> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1457624241-20525-1-git-send-email-ygardi@codeaurora.org> References: <1457624241-20525-1-git-send-email-ygardi@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1668 Lines: 46 When control reaches to Linux UFS driver during UFS boot mode, UFS host controller interrupt status/enable registers may have left over settings. In order to avoid any spurious interrupts due to these left overs, it's important to clear these interrupt status/enable registers before enabling UFS interrupt handling. Reviewed-by: Hannes Reinecke Signed-off-by: Subhash Jadavani Signed-off-by: Yaniv Gardi --- drivers/scsi/ufs/ufshcd.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a8e42df..de7280c 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5837,6 +5837,21 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) init_waitqueue_head(&hba->dev_cmd.tag_wq); ufshcd_init_clk_gating(hba); + + /* + * In order to avoid any spurious interrupt immediately after + * registering UFS controller interrupt handler, clear any pending UFS + * interrupt status and disable all the UFS interrupts. + */ + ufshcd_writel(hba, ufshcd_readl(hba, REG_INTERRUPT_STATUS), + REG_INTERRUPT_STATUS); + ufshcd_writel(hba, 0, REG_INTERRUPT_ENABLE); + /* + * Make sure that UFS interrupts are disabled and any pending interrupt + * status is cleared before registering UFS interrupt handler. + */ + mb(); + /* IRQ registration */ err = devm_request_irq(dev, irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba); if (err) { -- 1.8.5.2 -- QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation