RE: [PATCH v4] tty: serial: add Freescale lpuart driver support

Lu Jingchang-B35083
2013-07-08T02:51:30Z

>-----Original Message-----
>From: Shawn Guo [mailto:shawn.guo@linaro.org]
>Sent: Friday, July 05, 2013 8:36 PM
>To: Lu Jingchang-B35083
>Cc: linux-serial@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
>gregkh@linuxfoundation.org; s.hauer@pengutronix.de
>Subject: Re: [PATCH v4] tty: serial: add Freescale lpuart driver support
>
>On Fri, Jul 05, 2013 at 09:39:03AM +0000, Lu Jingchang-B35083 wrote:
>> I explicitly removed the cr2 restore code on cleaning up the redundant
>code, and find it work well on normal operation.
>> Low level debug is not supported on Vybrid so I didn't notice that
>problem.
>> Will you fixing it? Or I submit a fix on it?
>
>I can send a fix for that. But before doing that, I would need your help
>to understand why we need to clear those UARTCR2 bits for setting up FIFO
>stuff at all. From my quick testing, at least console still works fine
>after removing all those UARTCR2 operations from lpuart_setup_watermark().
[Lu Jingchang-B35083]
The FIFO registers description in the RM says "This register must be written only when C2[RE] and
C2[TE] are cleared/not set and when the data buffer/FIFO is empty." So the code is added.

Best Regards,
Jingchang