From 8998ab8b020d6711f56634880b26b2b908d1340c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Michael=20Niew=C3=B6hner?= Date: Mon, 20 Jun 2022 21:22:27 +0200 Subject: [PATCH] mb/clevo/l140cu: work around PECI staying high when idle, blocking s0ix MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit According to Intel doc# 575683 the PECI bus should be low when idle and is pulled up by clients with strong drive. However, for unknown reasons the bus stays high on this board, blocking s0ix entry. The PECI reference schematic in the ASPEED AST2400 BMC datasheet (actually not related to this board) says that a pull-down is *required* for the idle state. This might be just a requirement of this BMC, since this is nowhere documented in Intel datasheets, schematics or elsewhere. However, configuring a weak pull-down (20 k) on the PECI pad indeed solves this problem for now. Change-Id: Ib5a6b0ad3553c2cf795037d6a1982102bcb04644 Signed-off-by: Michael Niewöhner Reviewed-on: https://review.coreboot.org/c/coreboot/+/68793 Reviewed-by: Angel Pons Tested-by: build bot (Jenkins) --- src/mainboard/clevo/cml-u/variants/l140cu/gpio.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/mainboard/clevo/cml-u/variants/l140cu/gpio.c b/src/mainboard/clevo/cml-u/variants/l140cu/gpio.c index fb658dddd4..258f07698e 100644 --- a/src/mainboard/clevo/cml-u/variants/l140cu/gpio.c +++ b/src/mainboard/clevo/cml-u/variants/l140cu/gpio.c @@ -233,6 +233,9 @@ static const struct pad_config gpio_table[] = { PAD_NC(GPP_H21, NONE), PAD_NC(GPP_H22, UP_20K), PAD_NC(GPP_H23, UP_20K), + + /* ------- GPIO Group CPU ------- */ + PAD_CFG_NF(PECI_IO, DN_20K, DEEP, NF1), /* PECI */ }; void variant_configure_gpios(void)