]> www.infradead.org Git - users/jedix/linux-maple.git/commit
arm64: dts: qcom: sdm845: Disable USB U1/U2 entry
authorPrashanth K <quic_prashk@quicinc.com>
Tue, 31 Dec 2024 08:11:08 +0000 (13:41 +0530)
committerBjorn Andersson <andersson@kernel.org>
Mon, 6 Jan 2025 23:04:16 +0000 (17:04 -0600)
commitc6b3c16f2c627a487653bc52d99b05a2bc453dc0
tree0d152da33c480ed2e67a509982cf6c28d6fa62f3
parent10b4593ba0f8b410d946d587828e6cae8f7cc78b
arm64: dts: qcom: sdm845: 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: Prashanth K <quic_prashk@quicinc.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20241231081115.3149850-11-quic_prashk@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
arch/arm64/boot/dts/qcom/sdm845.dtsi