From 19a22e3373092dbe64774c350ee8143030f1e19f Mon Sep 17 00:00:00 2001 From: Subrata Banik Date: Sun, 25 Aug 2024 01:35:20 +0530 Subject: soc/intel/adl: Prevent unconditional legacy COM ports initialization This patch eliminates the LPC_IOE_COMA_EN and LPC_IOE_COMB_EN IO enables from the io_enables variable in the pch_early_iorange_init() function because lpc_io_setup_comm_a_b() is intended to activate legacy COM ports like COM-A (0x3F8 - 0x3FF) and COM_B (0x2F8 - 0x2FF). These COM ports are being activated unconditionally, which is undesirable for the Intel Alder Lake platform and causes traffic over the IO bus. As a result, this code is being removed and platforms that select DRIVERS_UART_8250IO can activate legacy COM ports. BUG=b:354066052 TEST=Able to boot google/redrix to the operating system and confirm that there was no traffic over legacy COMs while being monitored using the eSPI analyzer. Change-Id: I7a6e38bd151f823d37c07ee89a800489122cc209 Signed-off-by: Subrata Banik Reviewed-on: https://review.coreboot.org/c/coreboot/+/84080 Reviewed-by: Eric Lai Reviewed-by: Dinesh Gehlot Tested-by: build bot (Jenkins) --- src/soc/intel/alderlake/bootblock/pch.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'src') diff --git a/src/soc/intel/alderlake/bootblock/pch.c b/src/soc/intel/alderlake/bootblock/pch.c index 9041052bbb..01153489c7 100644 --- a/src/soc/intel/alderlake/bootblock/pch.c +++ b/src/soc/intel/alderlake/bootblock/pch.c @@ -98,8 +98,7 @@ static void soc_config_acpibase(void) void pch_early_iorange_init(void) { - uint16_t io_enables = LPC_IOE_COMA_EN | LPC_IOE_COMB_EN | - LPC_IOE_LPT_EN | LPC_IOE_FDD_EN | + uint16_t io_enables = LPC_IOE_LPT_EN | LPC_IOE_FDD_EN | LPC_IOE_LGE_200 | LPC_IOE_HGE_208 | LPC_IOE_KBC_60_64 | LPC_IOE_EC_62_66 | LPC_IOE_SUPERIO_2E_2F | LPC_IOE_EC_4E_4F; -- cgit v1.2.3