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authorMario Scheithauer <mario.scheithauer@siemens.com>2023-03-17 10:02:54 +0100
committerLean Sheng Tan <sheng.tan@9elements.com>2023-03-21 11:19:21 +0000
commitfb4fdac64cfe05c9642cd93129dbbf23dde4ac51 (patch)
tree790c11309cf66c926171b8bd03627c84bf0335ab
parentfd4f8911c12cb28467054eb06896bae1e0337df0 (diff)
mb/siemens/mc_ehl4: Limit PCIe root port #4 and #5 speed to Gen 1
Due to a non-optimal RX signal (receive) on PCIe root port #4 (00:1c.3) and #5 (00:1c.4), the speed must be limit to Gen 1. BUG=none TEST=RX signal measured with oscilloscope Change-Id: I695c0ef961290676fe421b6efd631d6e94d6d556 Signed-off-by: Mario Scheithauer <mario.scheithauer@siemens.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/73767 Reviewed-by: Jan Samek <jan.samek@siemens.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com> Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>
-rw-r--r--src/mainboard/siemens/mc_ehl/variants/mc_ehl4/devicetree.cb4
1 files changed, 4 insertions, 0 deletions
diff --git a/src/mainboard/siemens/mc_ehl/variants/mc_ehl4/devicetree.cb b/src/mainboard/siemens/mc_ehl/variants/mc_ehl4/devicetree.cb
index 1bf99fd837..52da98e2e2 100644
--- a/src/mainboard/siemens/mc_ehl/variants/mc_ehl4/devicetree.cb
+++ b/src/mainboard/siemens/mc_ehl/variants/mc_ehl4/devicetree.cb
@@ -74,6 +74,10 @@ chip soc/intel/elkhartlake
register "PcieRpLtrDisable[3]" = "true"
register "PcieRpLtrDisable[4]" = "true"
+ # Determines PCIe root port speed
+ register "PcieRpPcieSpeed[3]" = "1"
+ register "PcieRpPcieSpeed[4]" = "1"
+
# Storage (SATA/SDCARD/EMMC) related UPDs
register "SataSalpSupport" = "0"
register "SataPortsEnable[0]" = "1"