* [PATCH] ucc_geth: fix ucc halt problem in half duplex mode
@ 2010-11-26 9:29 Li Yang
2010-11-29 2:37 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Li Yang @ 2010-11-26 9:29 UTC (permalink / raw)
To: linuxppc-dev, netdev, davem
Cc: Anton Vorontsov, Jean-Denis Boyer, Andreas Schmitz
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>
---
drivers/net/ucc_geth.h | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/net/ucc_geth.h b/drivers/net/ucc_geth.h
index 05a9558..a78b9c0 100644
--- a/drivers/net/ucc_geth.h
+++ b/drivers/net/ucc_geth.h
@@ -899,7 +899,8 @@ struct ucc_geth_hardware_statistics {
#define UCC_GETH_UTFS_INIT 512 /* Tx virtual FIFO size
*/
#define UCC_GETH_UTFET_INIT 256 /* 1/2 utfs */
-#define UCC_GETH_UTFTT_INIT 512
+#define UCC_GETH_UTFTT_INIT 256 /* 1/2 utfs
+ due to errata */
/* Gigabit Ethernet (1000 Mbps) */
#define UCC_GETH_URFS_GIGA_INIT 4096/*2048*/ /* Rx virtual
FIFO size */
--
1.6.6-rc1.GIT
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] ucc_geth: fix ucc halt problem in half duplex mode
2010-11-26 9:29 [PATCH] ucc_geth: fix ucc halt problem in half duplex mode Li Yang
@ 2010-11-29 2:37 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2010-11-29 2:37 UTC (permalink / raw)
To: leoli; +Cc: netdev, Andreas.Schmitz, avorontsov, linuxppc-dev, jdboyer
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.
^ permalink raw reply [flat|nested] 2+ messages in thread
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