[PATCH 5.4 132/340] i2c: iproc: handle only slave interrupts which are enabled

[Greg Kroah-Hartman]

From: Rayagonda Kokatanur <rayagonda.kokatanur@xxxxxxxxxxxx>

[ Upstream commit 545f4011e156554d704d6278245d54543f6680d1 ]

Handle only slave interrupts which are enabled.

The IS_OFFSET register contains the interrupt status bits which will be
set regardless of the enabling of the corresponding interrupt condition.
One must therefore look at both IS_OFFSET and IE_OFFSET to determine
whether an interrupt condition is set and enabled.

Fixes: c245d94ed106 ("i2c: iproc: Add multi byte read-write support for slave mode")
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@xxxxxxxxxxxx>
Acked-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/i2c/busses/i2c-bcm-iproc.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index dd9661c11782a..2983cd9f855b4 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -503,12 +503,17 @@ static void bcm_iproc_i2c_process_m_event(struct bcm_iproc_i2c_dev *iproc_i2c,
 static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
 {
 	struct bcm_iproc_i2c_dev *iproc_i2c = data;
-	u32 status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
+	u32 slave_status;
+	u32 status;
 	bool ret;
-	u32 sl_status = status & ISR_MASK_SLAVE;
 
-	if (sl_status) {
-		ret = bcm_iproc_i2c_slave_isr(iproc_i2c, sl_status);
+	status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
+	/* process only slave interrupt which are enabled */
+	slave_status = status & iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET) &
+		       ISR_MASK_SLAVE;
+
+	if (slave_status) {
+		ret = bcm_iproc_i2c_slave_isr(iproc_i2c, slave_status);
 		if (ret)
 			return IRQ_HANDLED;
 		else
-- 
2.27.0