[PATCH 3.16 050/125] i2c: rk3x: fix interrupt handling issue

Greg Kroah-Hartman
2014-09-03T22:23:16Z

From: addy ke <addy.ke@rock-chips.com>

commit 9c5f7cad3acc69ce623d04d646950183a759949e upstream.

If slave holds scl, I2C_IPD[7] will be set 1 by controller
for debugging. Driver must ignore it.

[ 5.752391] rk3x-i2c ff160000.i2c: unexpected irq in WRITE: 0x80
[ 5.939027] rk3x-i2c ff160000.i2c: timeout, ipd: 0x80, state: 4

Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/i2c/busses/i2c-rk3x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -399,7 +399,7 @@ static irqreturn_t rk3x_i2c_irq(int irqn
}

/* is there anything left to handle? */
- if (unlikely(ipd == 0))
+ if (unlikely((ipd & REG_INT_ALL) == 0))
goto out;

switch (i2c->state) {