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[U-Boot,2/7] powerpc/mpc8xxx: adjust DDR burst length and chop accroding to sdram width

Message ID 1306452353-11611-2-git-send-email-yorksun@freescale.com
State Accepted
Commit e090aa7cf05fe3cde7ce751cbb4f0c59cc113035
Delegated to: Kumar Gala
Headers show

Commit Message

York Sun May 26, 2011, 11:25 p.m. UTC 
From: york <yorksun@freescale.com>

If the bus width is 32-bit, burst chop should be disabled and burst length
should be 8. Read from SPD or other source to determine the width.

Signed-off-by: York Sun <yorksun@freescale.com>
---
 arch/powerpc/cpu/mpc8xxx/ddr/options.c |   24 ++++++++++++++++++++----
 1 files changed, 20 insertions(+), 4 deletions(-)

Comments

Kumar Gala June 3, 2011, 7:42 a.m. UTC | #1 
On May 26, 2011, at 6:25 PM, York Sun wrote:

> From: york <yorksun@freescale.com>
> 
> If the bus width is 32-bit, burst chop should be disabled and burst length
> should be 8. Read from SPD or other source to determine the width.
> 
> Signed-off-by: York Sun <yorksun@freescale.com>
> ---
> arch/powerpc/cpu/mpc8xxx/ddr/options.c |   24 ++++++++++++++++++++----
> 1 files changed, 20 insertions(+), 4 deletions(-)

applied to 85xx next

- k
diff mbox

Patch

diff --git a/arch/powerpc/cpu/mpc8xxx/ddr/options.c b/arch/powerpc/cpu/mpc8xxx/ddr/options.c
index 6ccc3b0..80c7046 100644
--- a/arch/powerpc/cpu/mpc8xxx/ddr/options.c
+++ b/arch/powerpc/cpu/mpc8xxx/ddr/options.c
@@ -418,8 +418,19 @@  unsigned int populate_memctl_options(int all_DIMMs_registered,
 	/* Choose dynamic power management mode. */
 	popts->dynamic_power = 0;
 
-	/* 0 = 64-bit, 1 = 32-bit, 2 = 16-bit */
-	popts->data_bus_width = 0;
+	/*
+	 * check first dimm for primary sdram width
+	 * presuming all dimms are similar
+	 * 0 = 64-bit, 1 = 32-bit, 2 = 16-bit
+	 */
+	if (pdimm[0].primary_sdram_width == 64)
+		popts->data_bus_width = 0;
+	else if (pdimm[0].primary_sdram_width == 32)
+		popts->data_bus_width = 1;
+	else if (pdimm[0].primary_sdram_width == 16)
+		popts->data_bus_width = 2;
+	else
+		panic("Error: invalid primary sdram width!\n");
 
 	/* Choose burst length. */
 #if defined(CONFIG_FSL_DDR3)
@@ -427,8 +438,13 @@  unsigned int populate_memctl_options(int all_DIMMs_registered,
 	popts->OTF_burst_chop_en = 0;	/* on-the-fly burst chop disable */
 	popts->burst_length = DDR_BL8;	/* Fixed 8-beat burst len */
 #else
-	popts->OTF_burst_chop_en = 1;	/* on-the-fly burst chop */
-	popts->burst_length = DDR_OTF;	/* on-the-fly BC4 and BL8 */
+	if (popts->data_bus_width == 1) {	/* 32-bit bus */
+		popts->OTF_burst_chop_en = 0;
+		popts->burst_length = DDR_BL8;
+	} else {
+		popts->OTF_burst_chop_en = 1;	/* on-the-fly burst chop */
+		popts->burst_length = DDR_OTF;	/* on-the-fly BC4 and BL8 */
+	}
 #endif
 #else
 	popts->burst_length = DDR_BL4;	/* has to be 4 for DDR2 */