]> www.infradead.org Git - users/jedix/linux-maple.git/commit
arm64: dts: qcom: sm8350: Disable USB U1/U2 entry
authorKrishna Kurapati <krishna.kurapati@oss.qualcomm.com>
Tue, 31 Dec 2024 08:10:59 +0000 (13:40 +0530)
committerBjorn Andersson <andersson@kernel.org>
Mon, 6 Jan 2025 23:04:15 +0000 (17:04 -0600)
commit8582f8cee2f015ff4b8c5df3221917f3878f4c2a
tree7e86abe5140b7dd4028686eb47bfc743f11e9e7e
parent6a02becf4b42f1664d9443e7d2049dd4e31e5ff5
arm64: dts: qcom: sm8350: Disable USB U1/U2 entry

Disable U1 and U2 power-saving states to improve stability of USB.
These low-power link states, designed to reduce power consumption
during idle periods, can cause issues in latency-sensitive or high
throughput use cases. Over the years, some of the issues seen are
as follows:

1. In device mode of operation, when UVC is active, enabling U1/U2
is sometimes causing packets drops due to delay in entry/exit of
intermittent these low power states. These packet drops are often
reflected as missed isochronous transfers, as the controller wasn't
able to send packet in that microframe interval and hence glitches
are seen on the final transmitted video output.

2. On older targets like SM8150/SM8250/SM8350, there have been
throughput issues seen during tethering use cases.

Disabling these intermittent power states enhances device stability
without affecting power usage.

Signed-off-by: Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20241231081115.3149850-2-quic_prashk@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
arch/arm64/boot/dts/qcom/sm8350.dtsi