dwc2 USB controller hangs with lan78xx
authorAndrew Thomas <andrew.thomas@oracle.com>
Mon, 18 Jun 2018 18:56:06 +0000 (11:56 -0700)
committerTom Rini <trini@konsulko.com>
Thu, 28 Jun 2018 02:21:25 +0000 (22:21 -0400)
commitaf15946aa081dbcd0bec7d507a2b2db4e6b6cda5
tree959969d9e40776a9094755a8c030ea60e77fd1f0
parentde76610545f4350f8e3eac7c0c4ff6349106a9bf
dwc2 USB controller hangs with lan78xx

This bug is the combination of dwc2 USB controller and lan78xx
USB ethernet controller, which is the combination in use on
the Raspberry Pi Model 3 B+.

When the host attempts to receive a packet, but a packet has not
arrived, the lan78xx controller responds by setting BIR
(Bulk-In Empty Response) to NAK. Unfortunately, this hangs
the USB controller and requires the USB controller to
be reset.

The fix proposed is to have the lan78xx controller respond
by setting BIR to ZLP.

Signed-off-by: Andrew Thomas <andrew.thomas@oracle.com>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
drivers/usb/eth/lan78xx.c