Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter in start_tx

From: SÃren Brinkmann
Date: Fri Nov 20 2015 - 12:05:19 EST

On Fri, 2015-11-20 at 07:13AM -0500, Peter Hurley wrote:
> On 11/19/2015 03:02 PM, Soren Brinkmann wrote:
> > start_tx must start transmitting characters. Regardless of the state of
> > the circular buffer, always enable the transmitter hardware.
> Why?
> Does cdns_uart_stop_tx() actually stop the transmitter so that
> data remains in the transmitter?

Fixing up the patch, I looked at this one. It might actually do that.
Without having changed anything. The doc says: "The driver should
stop transmitting characters as soon as possible.". And the
implementation is really not draining any FIFO, but just disabling the
transmitter. I take your question as that this might not be this way?
Should stop_tx drain the FIFO first?

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