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To: leoli@freescale.com
Subject: Re: [PATCH] ucc_geth: fix ucc halt problem in half duplex mode
From: David Miller <davem@davemloft.net>
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From: Li Yang <leoli@freescale.com>
Date: Fri, 26 Nov 2010 17:29:58 +0800

> In commit 58933c64(ucc_geth: Fix the wrong the Rx/Tx FIFO size),
> the UCC_GETH_UTFTT_INIT is set to 512 based on the recommendation
> of the QE Reference Manual.  But that will sometimes cause tx halt
> while working in half duplex mode.
> 
> According to errata draft QE_GENERAL-A003(High Tx Virtual FIFO
> threshold size can cause UCC to halt), setting UTFTT less than
> [(UTFS x (M - 8)/M) - 128] will prevent this from happening
> (M is the minimum buffer size).
> 
> The patch changes UTFTT back to 256.
> 
> Signed-off-by: Li Yang <leoli@freescale.com>
> Cc: Jean-Denis Boyer <jdboyer@media5corp.com>
> Cc: Andreas Schmitz <Andreas.Schmitz@riedel.net>
> Cc: Anton Vorontsov <avorontsov@ru.mvista.com>

Applied, thank you.