Hi:
On 2016年10月22日 16:43, David Wu wrote:
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 <david.wu@xxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxxxx>
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