[v6,2/5] i2c: ocores: do not handle IRQ if IF is not set
diff mbox series

Message ID 20190211164913.5988-3-federico.vaga@cern.ch
State Superseded
Headers show
  • i2c: ocores: improvements
Related show

Commit Message

Federico Vaga Feb. 11, 2019, 4:49 p.m. UTC
If the Interrupt Flag (IF) is not set, we should not handle the IRQ:
- the line can be shared with other devices
- it can be a spurious interrupt

To avoid reading twice the status register, the ocores_process() function
expects it to be read by the caller.

Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
 drivers/i2c/busses/i2c-ocores.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff mbox series

diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index aa85202..fcc2558 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -143,10 +143,9 @@  static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
 	return i2c->getreg(i2c, reg);
-static void ocores_process(struct ocores_i2c *i2c)
+static void ocores_process(struct ocores_i2c *i2c, u8 stat)
 	struct i2c_msg *msg = i2c->msg;
-	u8 stat = oc_getreg(i2c, OCI2C_STATUS);
 	unsigned long flags;
@@ -223,8 +222,12 @@  out:
 static irqreturn_t ocores_isr(int irq, void *dev_id)
 	struct ocores_i2c *i2c = dev_id;
+	u8 stat = oc_getreg(i2c, OCI2C_STATUS);
+	if (!(stat & OCI2C_STAT_IF))
+		return IRQ_NONE;
-	ocores_process(i2c);
+	ocores_process(i2c, stat);
 	return IRQ_HANDLED;