usb: dwc3: gadget: Disable GUSB2PHYCFG.SUSPHY for End Transfer
authorThinh Nguyen <Thinh.Nguyen@synopsys.com>
Thu, 10 Nov 2022 01:58:50 +0000 (17:58 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 22 Nov 2022 15:51:22 +0000 (16:51 +0100)
commit3aa07f72894d209fcf922ad686cbb28cf005aaad
tree9679c505eaf38e114bedb24bab832309b01380fe
parent181babf7b4e5050b7a23cb47eb06277405cf132f
usb: dwc3: gadget: Disable GUSB2PHYCFG.SUSPHY for End Transfer

If there's a disconnection while operating in eSS, there may be a delay
in VBUS drop response from the connector. In that case, the internal
link state may drop to operate in usb2 speed while the controller thinks
the VBUS is still high. The driver must make sure to disable
GUSB2PHYCFG.SUSPHY when sending endpoint command while in usb2 speed.
The End Transfer command may be called, and only that command needs to
go through at this point. Let's keep it simple and unconditionally
disable GUSB2PHYCFG.SUSPHY whenever we issue the command.

This scenario is not seen in real hardware. In a rare case, our
prototype type-c controller/interface may have a slow response
triggerring this issue.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/5651117207803c26e2f22ddf4e5ce9e865dcf7c7.1668045468.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/dwc3/gadget.c