From: Dave Liu <daveliu@freescale.com>
Date: Thu, 23 Oct 2008 13:18:53 +0000 (+0800)
Subject: 85xx: Fix the incorrect register used for DDR erratum1
X-Git-Tag: v2009.01-rc1~135
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=ae5f943ba8ede448a4b1a145fd8911856701ecc5;p=u-boot

85xx: Fix the incorrect register used for DDR erratum1

The 8572 DDR erratum1:
DDR controller may enter an illegal state when operating
in 32-bit bus mode with 4-beat bursts.

Description:
When operating with a 32-bit bus, it is recommended that
DDR_SDRAM_CFG[8_BE] is cleared when DDR2 memories are used.
This forces the DDR controller to use 4-beat bursts when
communicating to the DRAMs. However, an issue exists that
could lead to data corruption when the DDR controller is
in 32-bit bus mode while using 4-beat bursts.

Projected Impact:
If the DDR controller is operating in 32-bit bus mode with
4-beat bursts, then the controller may enter into a bad state.
All subsequent reads from memory is corrupted.
Four-beat bursts with a 32-bit bus only is used with DDR2 memories.
Therefore, this erratum does not affect DDR3 mode.

Work Arounds:
To work around this issue, software must set DEBUG_1[31] in
DDR memory mapped space (CCSRBAR offset + 0x2f00 for DDR_1
and CCSRBAR offset + 0x6f00 for DDR_2).

Currenlty, the code is using incorrect register DDR_SDRAM_CFG_2
as condition, but it should be DDR_SDRAM_CFG register.

Signed-off-by: Dave Liu <daveliu@freescale.com>
---

diff --git a/cpu/mpc85xx/ddr-gen3.c b/cpu/mpc85xx/ddr-gen3.c
index e0654bb3f8..a2b45c5719 100644
--- a/cpu/mpc85xx/ddr-gen3.c
+++ b/cpu/mpc85xx/ddr-gen3.c
@@ -79,15 +79,18 @@ void fsl_ddr_set_memctl_regs(const fsl_ddr_cfg_regs_t *regs,
 	out_be32(&ddr->ddr_sdram_rcw_2, regs->ddr_sdram_rcw_2);
 
 	/*
-	 * 32-bit workaround for DDR2
-	 * 32_BE
+	 * For 8572 DDR1 erratum - DDR controller may enter illegal state
+	 * when operatiing in 32-bit bus mode with 4-beat bursts,
+	 * This erratum does not affect DDR3 mode, only for DDR2 mode.
 	 */
+#ifdef CONFIG_MPC8572
 	if ((((in_be32(&ddr->sdram_cfg) >> 24) & 0x7) == SDRAM_TYPE_DDR2)
-	    && in_be32(&ddr->sdram_cfg_2) & 0x80000) {
+	    && in_be32(&ddr->sdram_cfg) & 0x80000) {
 		/* set DEBUG_1[31] */
 		u32 temp = in_be32(&ddr->debug_1);
 		out_be32(&ddr->debug_1, temp | 1);
 	}
+#endif
 
 	/*
 	 * 200 painful micro-seconds must elapse between