From 2fcdc6a23493c03c2abb8d24da6e9abcc1c7d026 Mon Sep 17 00:00:00 2001 From: Subhash Jadavani Date: Thu, 14 Aug 2014 17:56:47 -0700 Subject: [PATCH] scsi: ufs: avoid spurious UFS host controller interrupts 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. CRs-Fixed: 709250 Change-Id: Ibb554ca6e1bd2f69663a741f15948f80c52ce75c Signed-off-by: Subhash Jadavani --- 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 158b65ad5d79..9271caa07b7b 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -6743,6 +6743,21 @@ 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) { -- 2.11.0