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From: Tim Kryger <tim.kryger@gmail.com>
To: Alan Cox <alan@linux.intel.com>
Cc: "long.wanglong" <long.wanglong@huawei.com>,
	Peter Hurley <peter@hurleysoftware.com>,
	Zhang Zhen <zhenzhang.zhang@huawei.com>,
	linux-serial@vger.kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Tim Kryger <tim.kryger@linaro.org>,
	gregkh@linuxfoundation.org, Jamie Iles <jamie@jamieiles.com>,
	Arnd Bergmann <arnd@arndb.de>,
	shenjiangjiang@huawei.com, Wang Kai <morgan.wang@huawei.com>
Subject: Re: [RFC] With 8250 Designware UART, if writes to the LCR failed the kernel will hung up
Date: Mon, 9 Mar 2015 07:36:21 -0700	[thread overview]
Message-ID: <CAD7vxxJvL61BjD9AMBF34Y8xnY+D-umuWLUq8Dh7ZbSm5tCE9w@mail.gmail.com> (raw)
In-Reply-To: <1425907939.3838.182.camel@linux.intel.com>

On Mon, Mar 9, 2015 at 6:32 AM, Alan Cox <alan@linux.intel.com> wrote:
>> Maybe the next release of the board we will upgrade the serial block to the new version.
>> but the issue is that how we circumvent this problem in kernel?
>
> What is the official vendor workaround ?

They introduced a UART_16550_COMPATIBLE option for the IP which should
be selected.

If configured, writes to the LCR are allowed even if it is "busy" so
there is no need to retry.

More importantly there is no possibility of failing to write the LCR
after numerous retries.

-Tim

  reply	other threads:[~2015-03-09 14:36 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-06  9:11 Zhang Zhen
2015-03-06 16:50 ` Peter Hurley
2015-03-07  3:01   ` Tim Kryger
2015-03-09  7:10     ` long.wanglong
2015-03-09 13:32       ` Alan Cox
2015-03-09 14:36         ` Tim Kryger [this message]
2015-03-09 15:05           ` Alan Cox
2015-03-10  2:47             ` Tim Kryger
2015-03-10  3:15               ` Zhang Zhen
2015-03-10 13:25               ` Peter Hurley
2015-03-11  1:20                 ` Zhang Zhen
2015-03-13 15:36               ` Andy Shevchenko
2015-03-15 14:50                 ` Peter Hurley

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