Thread (5 messages) 5 messages, 4 authors, 2016-10-27
STALE3521d

[PATCH] i2c: rk3x: Give the tuning value 0 during rk3x_i2c_v0_calc_timings

From: David Wu <hidden>
Date: 2016-10-22 08:44:16
Also in: linux-arm-kernel, linux-i2c, linux-rockchip, lkml
Subsystem: arm/rockchip soc support, i2c subsystem, i2c subsystem host drivers, the rest · Maintainers: Heiko Stuebner, Andi Shyti, Linus Torvalds

We found a bug that i2c transfer sometimes failed on 3066a board with
stabel-4.8, the con register would be updated by uninitialized tuning
value, it made the i2c transfer failed.

So give the tuning value to be zero during rk3x_i2c_v0_calc_timings.

Signed-off-by: David Wu <redacted>
---
 drivers/i2c/busses/i2c-rk3x.c | 2 ++
 1 file changed, 2 insertions(+)
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 50702c7..df22066 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -694,6 +694,8 @@ static int rk3x_i2c_v0_calc_timings(unsigned long clk_rate,
 	t_calc->div_low--;
 	t_calc->div_high--;
 
+	/* Give the tuning value 0, that would not update con register */
+	t_calc->tuning = 0;
 	/* Maximum divider supported by hw is 0xffff */
 	if (t_calc->div_low > 0xffff) {
 		t_calc->div_low = 0xffff;
-- 
1.9.1


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