===========
Subject: Enable XLB pipelining for MPC5200B
From: Wolfram Sang <w.sang@pengutronix.de>
Enable pipelining as it helps getting rid of FEC problems.
Not intended for upstream, this must be dealt differently there.
This patch is disabled by default. The bootloader should enable this feature.
So, this patch is only intended to be used where the bootloader does it in a
wrong manner and can't be replaced.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Juergen Beisert <j.beisert@pengutronix.de>
---
arch/powerpc/platforms/52xx/mpc52xx_common.c | 7 +++++++
1 file changed, 7 insertions(+)
===================================================================
@@ -107,6 +107,13 @@ mpc5200_setup_xlb_arbiter(void)
*/
if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR)
out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
+#if 0
+ /*
+ * Enable pipelining, fixes FEC problems. The previous workaround is not
+ * needed, as we have an MPC5200B (not A).
+ */
+ out_be32(&xlb->config, in_be32(&xlb->config) & ~MPC52xx_XLB_CFG_PLDIS);
+#endif
iounmap(xlb);
}