[PATCH v6 02/17] scsi: ufs: avoid spurious UFS host controller interrupts

[Yaniv Gardi]

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 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(>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

[PATCH v6 02/17] scsi: ufs: avoid spurious UFS host controller interrupts

[Yaniv Gardi]

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 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(>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