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authorMatt DeVillier <matt.devillier@gmail.com>2017-02-16 11:36:16 -0600
committerMartin Roth <martinroth@google.com>2017-02-20 04:44:22 +0100
commitc97e042a9bda9994409869369e1cbda551dc65cf (patch)
tree42f7a288dbcc63e953a82f7c3ed21b6ec6bba0f6 /src/southbridge
parentee6a612eb2edb32a55ee92c6fdfcdc474c6b21f1 (diff)
downloadcoreboot-c97e042a9bda9994409869369e1cbda551dc65cf.tar.xz
lynxpoint/broadwell: fix PCH power optimizer
Setting both bits 27 and 7 of PCH register PMSYNC_CFG (PMSYNC Configuration; offset 0x33c8) causes pre-OS display init to fail on HSW-U/Lynxpoint and BDW-U ChromeOS devices when the VBIOS/GOP driver is run after the register is set. A re-examination of Intel's reference code reveals that bit 7 should be set for the LP PCH, and bit 27 for non-LP, but not both simultaneously. The previous workaround was to disable the entire power optimizer section via a Kconfig option, which isn't ideal. Test: unset bit 27 of PMSYNC_CFG and boot google/lulu, observe functional pre-OS video output Change-Id: I446e169d23dd446710a1648f0a9b9599568b80aa Signed-off-by: Matt DeVillier <matt.devillier@gmail.com> Reviewed-on: https://review.coreboot.org/18385 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth <martinroth@google.com> Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Diffstat (limited to 'src/southbridge')
-rw-r--r--src/southbridge/intel/lynxpoint/lpc.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/src/southbridge/intel/lynxpoint/lpc.c b/src/southbridge/intel/lynxpoint/lpc.c
index 04cb0bd504..d295c888f8 100644
--- a/src/southbridge/intel/lynxpoint/lpc.c
+++ b/src/southbridge/intel/lynxpoint/lpc.c
@@ -347,7 +347,7 @@ const struct rcba_config_instruction lpt_lp_pm_rcba[] = {
RCBA_RMW_REG_32(0x3350, 0, 0x022ddfff),
RCBA_RMW_REG_32(0x3354, 0, 0x00000001),
RCBA_RMW_REG_32(0x33d4, ~0, 0x08000000), /* Power Optimizer */
- RCBA_RMW_REG_32(0x33c8, ~0, 0x08000080), /* Power Optimizer */
+ RCBA_RMW_REG_32(0x33c8, ~0, 0x00000080), /* Power Optimizer */
RCBA_RMW_REG_32(0x2b10, 0, 0x0000883c), /* Power Optimizer */
RCBA_RMW_REG_32(0x2b14, 0, 0x1e0a4616), /* Power Optimizer */
RCBA_RMW_REG_32(0x2b24, 0, 0x40000005), /* Power Optimizer */