Hi Jonas,
On 10/19/25 5:09 PM, Jonas Karlman wrote:
The RK3568 SoC comes with USB OTG support using a DWC3 controller with
a USB2 PHY and a USB3 PHY (COMBPHY).
Some board designs may not use the COMBPHY for USB3 purpose. For these
board to use USB OTG the input clock source must change to use UTMI clk
instead of PIPE clk.
Change to always disable the USB3OTG U3 ports early and leave it to the
COMBPHY driver to re-enable the U3 port when a usb3-phy is described in
the board device tree.
Please note that this may break use of USB 3.0 on RK3568 on Linux kernel
prior to version 6.6.112, 6.12.53, 6.17.3 and 6.18-rc1.
Signed-off-by: Jonas Karlman <[email protected]>
---
It may be too soon to apply this patch, we should possible give more
time for OS to adopt to these changes.
The first patch in this series should however be safe to apply.
What's the cost of *NOT* applying this? I imagine if the PHY isn't used
in the kernel it can be turned off by runtime PM? So would that be only
about reducing power consumption while in U-Boot?
It may not be worth it to possibly break devices if we're simply talking
about power efficiency for a boot stage that shouldn't last long anyway.
We cannot know what the user will be booting as kernel so there
technically is not a safe date when this could be merged.
Cheers,
Quentin
