[PATCH 4.4 22/37] i2c: rcar: check master irqs before slave irqs

Greg Kroah-Hartman
2018-06-05T17:03:35Z

From: Wolfram Sang <wsa+renesas@sang-engineering.com>

commit c3be0af15959e11fa535d5332ab3d7cf34abd09b upstream.

Due to the HW design, master IRQs are timing critical, so give them
precedence over slave IRQ.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/i2c/busses/i2c-rcar.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -432,19 +432,17 @@ static bool rcar_i2c_slave_irq(struct rc
static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
{
struct rcar_i2c_priv *priv = ptr;
- irqreturn_t result = IRQ_HANDLED;
u32 msr;

- if (rcar_i2c_slave_irq(priv))
- goto exit;
-
msr = rcar_i2c_read(priv, ICMSR);

/* Only handle interrupts that are currently enabled */
msr &= rcar_i2c_read(priv, ICMIER);
if (!msr) {
- result = IRQ_NONE;
- goto exit;
+ if (rcar_i2c_slave_irq(priv))
+ return IRQ_HANDLED;
+
+ return IRQ_NONE;
}

/* Arbitration lost */
@@ -481,8 +479,7 @@ out:
wake_up(&priv->wait);
}

-exit:
- return result;
+ return IRQ_HANDLED;
}

static int rcar_i2c_master_xfer(struct i2c_adapter *adap,