[PATCH 05/10] arm64: dts: qcom: sc8280xp-x13s: limit pcie4 link speed

Johan Hovold
2024-02-12T16:53:39Z

Limit the WiFi PCIe link speed to Gen2 speed (500 GB/s), which is the
speed that the boot firmware has brought up the link at (and that
Windows uses).

This is specifically needed to avoid a large amount of link errors when
restarting the link during boot (but which are currently not reported).

This may potentially also help with intermittent failures to download
the ath11k firmware during boot which can be seen when there is a
longer delay between restarting the link and loading the WiFi driver
(e.g. when using full disk encryption).

Fixes: 123b30a75623 ("arm64: dts: qcom: sc8280xp-x13s: enable WiFi controller")
Cc: stable@vger.kernel.org # 6.2
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
index 511d53d9c5a1..ff4b896b1bbf 100644
--- a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
+++ b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
@@ -863,6 +863,8 @@ &pcie3a_phy {
};

&pcie4 {
+ max-link-speed = <2>;
+
perst-gpios = <&tlmm 141 GPIO_ACTIVE_LOW>;
wake-gpios = <&tlmm 139 GPIO_ACTIVE_LOW>;

--
2.43.0