linux-kernel - Re: [PATCH V9 4/4] USB: serial: f81232: implement break control

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Message-ID: <84cff579-79bd-9456-aa85-cb4510d916ed@gmail.com>
Date:   Mon, 6 May 2019 10:52:27 +0800
From:   "Ji-Ze Hong (Peter Hong)" <hpeter@...il.com>
To:     Johan Hovold <johan@...nel.org>
Cc:     peter_hong@...tek.com.tw, gregkh@...uxfoundation.org,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        "Ji-Ze Hong (Peter Hong)" <hpeter+linux_kernel@...il.com>
Subject: Re: [PATCH V9 4/4] USB: serial: f81232: implement break control

Hi Johan,

Johan Hovold 於 2019/5/3 下午 02:59 寫道:
>> @@ -519,6 +530,7 @@ static int f81232_port_disable(struct usb_serial_port *port)
>>   static void f81232_set_termios(struct tty_struct *tty,
>>   		struct usb_serial_port *port, struct ktermios *old_termios)
>>   {
>> +	struct f81232_private *priv = usb_get_serial_port_data(port);
>>   	u8 new_lcr = 0;
>>   	int status = 0;
>>   	speed_t baudrate;
>> @@ -572,11 +584,16 @@ static void f81232_set_termios(struct tty_struct *tty,
>>   		break;
>>   	}
>>   
>> +	mutex_lock(&priv->lock);
>> +
>> +	new_lcr |= (priv->shadow_lcr & UART_LCR_SBC);
>>   	status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
>>   	if (status) {
>>   		dev_err(&port->dev, "%s failed to set LCR: %d\n",
>>   			__func__, status);
>>   	}
>> +
>> +	mutex_unlock(&priv->lock);
> 
> You forgot to update shadow_lcr here so the line settings would be
> corrupted (e.g set to 5 bit words) whenever a break is signalled.
> 
> Did you not test this version of the patch?
> 
> I added the missing update, but please test the code that's in my
> usb-next branch in a minute and confirm everything works as expected.
> 

Thanks for mention and patch the lost parts. I had only tested the
break signal and forgot to test full LCR. I'll add it to my test items
and it tested well on new usb-next branch after your fix.

BTW, Should I disable break control when port close ?

Thanks.

-- 
With Best Regards,
Peter Hong