[PATCH] usb: dwc3: apple: Ignore USB role switches to the active role
Sven Peter
sven at kernel.org
Mon Jan 12 22:58:56 PST 2026
On 09.01.26 11:13, Janne Grunau wrote:
> Ignore USB role switches if dwc3-apple is already in the desired state.
> The USB-C port controller on M2 and M1/M2 Pro/Max/Ultra devices issues
> additional interrupts which result in USB role switches to the already
> active role.
> Ignore these USB role switches to ensure the USB-C port controller and
> dwc3-apple are always in a consistent state. This matches the behaviour
> in __dwc3_set_mode() in core.c.
> Fixes detecting USB 2.0 and 3.x devices on the affected systems. The
> reset caused by the additional role switch appears to leave the USB
> devices in a state which prevents detection when the phy and dwc3 is
> brought back up again.
>
> Fixes: 0ec946d32ef7 ("usb: dwc3: Add Apple Silicon DWC3 glue layer driver")
> Cc: stable at vger.kernel.org
> Signed-off-by: Janne Grunau <j at jannau.net>
> ---
Reviewed-by: Sven Peter <sven at kernel.org>
Tested-by: Sven Peter <sven at kernel.org> # M1 mac mini and macbook air
thanks,
Sven
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