[PATCH] MPC52XX: Don't touch pipelining for MPC5200B

Wolfram Sang w.sang at pengutronix.de
Mon Aug 18 19:31:32 EST 2008


MPC5200 needs to have pipelining disabled for ATA to work. MPC5200B does not.
So, for the latter, don't touch the original setting from the bootloader.

Signed-off-by: Wolfram Sang <w.sang at pengutronix.de>
---

This needs some testing IMHO. Most configs in U-Boot tend to enable pipelining,
which then used to be disabled by the kernel. So, on the one hand, this change
would enable what is originally wanted; on the other hand, systems may run
under a new configuration and need to be checked for regressions. Especially as
there can be puzzling effects, like for one setup here, FEC only works reliably
with pipelining enabled.

 arch/powerpc/platforms/52xx/mpc52xx_common.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: playground/arch/powerpc/platforms/52xx/mpc52xx_common.c
===================================================================
--- playground.orig/arch/powerpc/platforms/52xx/mpc52xx_common.c
+++ playground/arch/powerpc/platforms/52xx/mpc52xx_common.c
@@ -99,12 +99,13 @@
 	out_be32(&xlb->master_pri_enable, 0xff);
 	out_be32(&xlb->master_priority, 0x11111111);
 
+#if defined(CONFIG_PPC_MPC5200_BUGFIX)
 	/* Disable XLB pipelining
 	 * (cfr errate 292. We could do this only just before ATA PIO
 	 *  transaction and re-enable it afterwards ...)
 	 */
 	out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
-
+#endif
 	iounmap(xlb);
 }
 
-- 
  Dipl.-Ing. Wolfram Sang | http://www.pengutronix.de
 Pengutronix - Linux Solutions for Science and Industry
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