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: 0ec946d32e ("usb: dwc3: Add Apple Silicon DWC3 glue layer driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Janne Grunau <j@jannau.net>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Reviewed-by: Sven Peter <sven@kernel.org>
Tested-by: Sven Peter <sven@kernel.org> # M1 mac mini and macbook air
Link: https://patch.msgid.link/20260109-apple-dwc3-role-switch-v1-1-11623b0f6222@jannau.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that the upstream code has been getting broader test coverage by our
users we occasionally see issues with USB2 devices plugged in during boot.
Before Linux is running, the USB2 PHY has usually been running in device
mode and it turns out that sometimes host->device or device->host
transitions don't work.
The root cause: If the role inside the USB2 PHY is re-configured when it
has already been powered on or when dwc3 has already enabled the ULPI
interface the new configuration sometimes doesn't take affect until dwc3
is reset again. Fix this rare issue by configuring the role much earlier.
Note that the USB3 PHY does not suffer from this issue and actually
requires dwc3 to be up before the correct role can be configured there.
Reported-by: James Calligeros <jcalligeros99@gmail.com>
Reported-by: Janne Grunau <j@jannau.net>
Fixes: 0ec946d32e ("usb: dwc3: Add Apple Silicon DWC3 glue layer driver")
Cc: stable <stable@kernel.org>
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Janne Grunau <j@jannau.net>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Sven Peter <sven@kernel.org>
Link: https://patch.msgid.link/20260109-dwc3-apple-usb2phy-fix-v2-1-ab6b041e3b26@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dwc3 controller present on Apple Silicon SoCs like the M1 requires
a specific order of operations synchronized between its PHY and its
Type-C controller. Specifically, the PHY first has to go through initial
bringup (which requires knowledge of the lane mode and orientation)
before dwc3 itself can be brought up and can then finalize the PHY
configuration.
Additionally, dwc3 has to be teared down and re-initialized whenever
the cable is changed due to hardware quirks that prevent a new device
from being recognized and due to the PHY being unable to switch lane
mode or orientation while dwc3 is up and running.
These controllers also have a Apple-specific MMIO region after the
common dwc3 region where some controls have to be updated. PHY bringup
and shutdown also requires SUSPHY to be enabled for the ports to work
correctly.
In the future, this driver will also gain support for USB3-via-USB4
tunneling which will require additional tweaks.
Add a glue driver that takes of all of these constraints.
Reviewed-by: Neal Gompa <neal@gompa.dev>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Sven Peter <sven@kernel.org>
Link: https://patch.msgid.link/20251015-b4-aplpe-dwc3-v2-5-cbd65a2d511a@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
