Re: [PATCH] i2c: rk3x: Give the tuning value 0 during rk3x_i2c_v0_calc_timings
From: Andy Yan <andy.yan@rock-chips.com>
Date: 2016-10-24 11:55:48
Also in:
linux-arm-kernel, linux-i2c, linux-rockchip, lkml
Hi: On 2016年10月22日 16:43, David Wu wrote:
quoted hunk ↗ jump to hunk
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;
rk3066a based board can't boot up(with endless i2c irq messages print out) from linux-4.8 without this fix. Tested-by: Andy Yan <andy.yan@rock-chips.com>