Re: [PATCH] Powerpc 8xx CPM_UART delay in receive

From: Alan Cox
Date: Tue Aug 14 2012 - 10:48:18 EST


On Tue, 14 Aug 2012 16:26:28 +0200
Christophe Leroy <christophe.leroy@xxxxxx> wrote:

> Hello,
>
> I'm not sure who to address this Patch to either
>
> It fixes a delay issue with CPM UART driver on Powerpc MPC8xx.
> The problem is that with the actual code, the driver waits 32 IDLE patterns before returning the received data to the upper level. It means for instance about 1 second at 300 bauds.
> This fix limits to one byte the waiting period.

Take a look how the 8250 does it - I think you want to set the value
based upon the data rate. Your patch will break it for everyone doing
high seed I/O.

Alan
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