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/soc/intel/broadwell/lpc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/soc') diff --git a/src/soc/intel/broadwell/lpc.c b/src/soc/intel/broadwell/lpc.c index c1600c5370..610b9772ee 100644 --- a/src/soc/intel/broadwell/lpc.c +++ b/src/soc/intel/broadwell/lpc.c @@ -262,7 +262,7 @@ static const struct reg_script pch_pm_init_script[] = { REG_MMIO_WRITE32(RCBA_BASE_ADDRESS + 0x3354, 0x00000001), /* Power Optimizer */ REG_MMIO_OR32(RCBA_BASE_ADDRESS + 0x33d4, 0x08000000), - REG_MMIO_OR32(RCBA_BASE_ADDRESS + 0x33c8, 0x08000080), + REG_MMIO_OR32(RCBA_BASE_ADDRESS + 0x33c8, 0x00000080), REG_MMIO_WRITE32(RCBA_BASE_ADDRESS + 0x2b10, 0x0000883c), REG_MMIO_WRITE32(RCBA_BASE_ADDRESS + 0x2b14, 0x1e0a4616), REG_MMIO_WRITE32(RCBA_BASE_ADDRESS + 0x2b24, 0x40000005), -- cgit v1.2.3