From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yaniv Gardi Subject: [PATCH v1 04/17] scsi: ufs: avoid spurious UFS host controller interrupts Date: Sun, 13 Sep 2015 17:52:44 +0300 Message-ID: <1442155977-7686-5-git-send-email-ygardi@codeaurora.org> References: <1442155977-7686-1-git-send-email-ygardi@codeaurora.org> Return-path: In-Reply-To: <1442155977-7686-1-git-send-email-ygardi@codeaurora.org> Sender: linux-scsi-owner@vger.kernel.org To: James.Bottomley@HansenPartnership.com, pebolle@tiscali.nl, hch@infradead.org 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, subhashj@codeaurora.org, ygardi@codeaurora.org, gbroner@codeaurora.org, draviv@codeaurora.org, Vinayak Holikatti , "James E.J. Bottomley" List-Id: linux-arm-msm@vger.kernel.org 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. 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 9e3ec01..7d20dac 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5886,6 +5886,21 @@ 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