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pistachio: Remove 50% DDR bandwidth restriction 

The existing DDR setup configures the burst length to be 8. However
the DDR controller can only be given sufficient data per clock to
satisfy a burst length of 4, hence the bursts are only half
populated. This results in a 50% drop of efficiency.

Fix this by configuring the burst size to 4.

BUG=chrome-os-partner:31438, chrome-os-partner:37087
TEST=tested on Pistachio bring up board -> DDR initialized
     properly and ramstage executed correctly
BRANCH=none

Change-Id: I761ba73a04688841ca39a370b7cb99b6e0b22964
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 0e590ab8387dbbccef45dc84d1eeafee2abc9e2e
Original-Change-Id: I585385b65e330624ad70292349e50c6695eeeb6c
Original-Signed-off-by: Ionela Voinescu <ionela.voinescu@imgtec.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/256305
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/9847
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
This commit is contained in:
Ionela Voinescu 2015-03-05 17:25:48 +00:00 committed by Patrick Georgi
parent 51ad6ac695
commit 823f6072a7
1 changed files with 1 additions and 1 deletions
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2
src/soc/imgtec/pistachio/ddr2_init.c
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@ -119,7 +119,7 @@
#define DDRPHY_BISTUDPR_OFFSET (0x0120)
#define DDRPHY_DLLGCR_OFFSET (0x0010)
#define BL8 1
#define BL8 0
#define DDR_TIMEOUT_VALUE_US 100000