usb: dwc3: Soft reset phy on probe for host
authorThinh Nguyen <Thinh.Nguyen@synopsys.com>
Wed, 13 Sep 2023 00:52:15 +0000 (00:52 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 19 Oct 2023 21:08:54 +0000 (23:08 +0200)
commit357191036889f2cc5453bf50101130e4f60ad221
tree97e48e018178515a5f3096f4267200ca101deac0
parentea9ae69b0e116809bf443a83bb487b37cbad85f6
usb: dwc3: Soft reset phy on probe for host

commit 8bea147dfdf823eaa8d3baeccc7aeb041b41944b upstream.

When there's phy initialization, we need to initiate a soft-reset
sequence. That's done through USBCMD.HCRST in the xHCI driver and its
initialization, However, the dwc3 driver may modify core configs before
the soft-reset. This may result in some connection instability. So,
ensure the phy is ready before the controller updates the GCTL.PRTCAPDIR
or other settings by issuing phy soft-reset.

Note that some host-mode configurations may not expose device registers
to initiate the controller soft-reset (via DCTL.CoreSftRst). So we reset
through GUSB3PIPECTL and GUSB2PHYCFG instead.

Cc: stable@vger.kernel.org
Fixes: e835c0a4e23c ("usb: dwc3: don't reset device side if dwc3 was configured as host-only")
Reported-by: Kenta Sato <tosainu.maple@gmail.com>
Closes: https://lore.kernel.org/linux-usb/ZPUciRLUcjDywMVS@debian.me/
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Tested-by: Kenta Sato <tosainu.maple@gmail.com>
Link: https://lore.kernel.org/r/70aea513215d273669152696cc02b20ddcdb6f1a.1694564261.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/dwc3/core.c