From c97e042a9bda9994409869369e1cbda551dc65cf Mon Sep 17 00:00:00 2001 From: Matt DeVillier Date: Thu, 16 Feb 2017 11:36:16 -0600 Subject: 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 Reviewed-on: https://review.coreboot.org/18385 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth Reviewed-by: Duncan Laurie --- src/southbridge/intel/lynxpoint/lpc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/southbridge/intel/lynxpoint') 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 */ -- cgit v1.2.3