From bea563e3288d3cae4cab410cf818552abbd3bba4 Mon Sep 17 00:00:00 2001 From: Nicholas Chin Date: Mon, 20 May 2024 10:24:16 -0600 Subject: [PATCH 18/35] mb/dell/e6400: Use 100 MHz reference clock for display The E6400 uses a 100 MHz reference clock for spread spectrum support on LVDS, whereas libgfxinit previously assumed a 96 MHz input clock. For the more common 1280 x 800 display panels, the numerical error was not large enough to cause noticable issues, but the actual pixel clock frequency derived from a 100 MHz reference using PLL configs calculated assuming a 96 MHz reference was not close enough for 1440 x 900 panels, which require a much higher pixel clock. This resulted in a garbled display in the pre-OS graphics environment provided by libgfxinit. Signed-off-by: Nicholas Chin --- src/mainboard/dell/gm45_latitude/Kconfig | 2 ++ src/northbridge/intel/gm45/Kconfig | 4 ++++ 2 files changed, 6 insertions(+) diff --git a/src/mainboard/dell/gm45_latitude/Kconfig b/src/mainboard/dell/gm45_latitude/Kconfig index 98ad18849c..4b026be2ba 100644 --- a/src/mainboard/dell/gm45_latitude/Kconfig +++ b/src/mainboard/dell/gm45_latitude/Kconfig @@ -21,6 +21,8 @@ config BOARD_DELL_E6400 select BOARD_DELL_GM45_LATITUDE_COMMON if BOARD_DELL_GM45_LATITUDE_COMMON +config INTEL_GMA_DPLL_REF_FREQ + default 100000000 config MAINBOARD_DIR default "dell/gm45_latitude" diff --git a/src/northbridge/intel/gm45/Kconfig b/src/northbridge/intel/gm45/Kconfig index fef0d735b3..fc5df8b11a 100644 --- a/src/northbridge/intel/gm45/Kconfig +++ b/src/northbridge/intel/gm45/Kconfig @@ -14,6 +14,10 @@ config NORTHBRIDGE_INTEL_GM45 if NORTHBRIDGE_INTEL_GM45 +config INTEL_GMA_DPLL_REF_FREQ + int + default 96000000 + config VBOOT select VBOOT_STARTS_IN_BOOTBLOCK -- 2.39.5