[PATCH][RFC] 8250_dw: unregister dw8250_set_termios for rk3188 chip

[Ed Blake]

On 21/11/17 03:09, Shuyu Wei wrote:
> On Mon, Nov 20, 2017 at 06:51:37PM +0100, Heiko Stübner wrote:
>  
>> Also, the rk3188 uarts are definitly not fixed at 24MHz and can use other 
>> sources as well. So I'm puzzled because at least the serial console on my 
>> rk3188 radxarock works without issues.
>>
>> Can you tell us which uart you are failing to control correctly?
>>
>>
>> I do remember that I ran into problems when the set_termios change
>> was introduced originally, resulting in the patch
>> 	"serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios" [0]
>> but that is in mainline for quite some time now.
>>
>> [0] https://patchwork.kernel.org/patch/9594657/
>>
>>
>> Heiko
> Hi Heiko,
>
> I'm using ttyS2(uart2).
> My board starts to fail on mainline since the exact commit 37c8596,
> that's why I try to remove dw8250_set_termios() and it worked.

Is this on 4.14 or next?

What baud rate is being set, and what rate does clk_round_rate() return
in dw8250_set_termios()?

Can you try applying this patch series and see if it fixes the problem?

https://www.spinics.net/lists/linux-serial/msg27672.html