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authorDuncan Laurie <dlaurie@google.com>2020-07-24 12:37:22 -0700
committerPatrick Georgi <pgeorgi@google.com>2020-07-29 09:36:11 +0000
commit3715785a49de6c0220f4c832130764fe9f72b570 (patch)
tree96fb850f3b5855b6f379eb51e6035b8e37abe87c /src
parent70b73cfc7869179cd1ddff1bd5b2c28db608fc6c (diff)
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 <dlaurie@google.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/43831 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Diffstat (limited to 'src')
-rw-r--r--src/soc/intel/tigerlake/include/soc/usb.h2
1 files changed, 1 insertions, 1 deletions
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, \
}