From 3715785a49de6c0220f4c832130764fe9f72b570 Mon Sep 17 00:00:00 2001 From: Duncan Laurie Date: Fri, 24 Jul 2020 12:37:22 -0700 Subject: soc/intel/tigerlake: Set default USB3 de-emphasis to -3.5dB The HSIO tuning guide recommendation for the default USB3 settings is to have de-emphasis set to -3.5dB with the equation 20*log(X/64). 0x29 results in a value close to -3.5dB and it is the value that was used for the default on past platforms so I used it here as well. BUG=b:160721468 TEST=Ensure WWAN device does not disconnect during use. Change-Id: Ia594996cb55523dacce0d4bef98cc217321c62de Signed-off-by: Duncan Laurie Reviewed-on: https://review.coreboot.org/c/coreboot/+/43831 Tested-by: build bot (Jenkins) Reviewed-by: Angel Pons --- src/soc/intel/tigerlake/include/soc/usb.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src') diff --git a/src/soc/intel/tigerlake/include/soc/usb.h b/src/soc/intel/tigerlake/include/soc/usb.h index 247b0ba554..d4836c9144 100644 --- a/src/soc/intel/tigerlake/include/soc/usb.h +++ b/src/soc/intel/tigerlake/include/soc/usb.h @@ -132,7 +132,7 @@ struct usb3_port_config { #define USB3_PORT_DEFAULT(pin) { \ .enable = 1, \ .ocpin = (pin), \ - .tx_de_emp = 0x0, \ + .tx_de_emp = 0x29, \ .tx_downscale_amp = 0x00, \ } -- cgit v1.2.3