Re: [PATCH V6 08/10] USB: f81232: fix read MSR strange value

From: Peter Hung <hpeter@gmail.com>
To: Johan Hovold <johan@kernel.org>
Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org, tom_tsai@fintek.com.tw,
	peter_hong@fintek.com.tw,
	Peter Hung <hpeter+linux_kernel@gmail.com>
Subject: Re: [PATCH V6 08/10] USB: f81232: fix read MSR strange value
Date: Tue, 24 Feb 2015 10:17:06 +0800	[thread overview]
Message-ID: <54EBDF22.3010804@gmail.com> (raw)
In-Reply-To: <20150217095136.GU2551@localhost>

Hello,

Johan Hovold 於 2015/2/17 下午 05:51 寫道:

>> So we add more check not only UART_MSR_ANY_DELTA but also with
>> comparing DCD/RI/DSR/CTS change with old value. Due to the state
>> bit is always correct, we direct save msr when read.
>>
>> The following step to reproduce this problem with while loop step 1~4:
>> 1. ioctl(fd, TIOCMSET, &data) to set RTS or DTR
>> 2. ioctl(fd, TIOCMGET, &data) to read CTS or DCD/DSR state
>> 3. ioctl(fd, TIOCMSET, &data) to unset RTS or DTR
>> 4. ioctl(fd, TIOCMGET, &data) to read CTS or DCD/DSR state
>
> Without having looked at this very closely; are you sure this is a
> hardware issue and not related to the locking issues I pointed at in my
> comments to tiocmset?
>
> Johan
>

Thank for your review.

I'll apply all suggestions to next v7 patch.

-- 
With Best Regards,
Peter Hung