usb: ulpi: defer ulpi_register on ulpi_read_id timeout
authorFerry Toth <ftoth@exalondelft.nl>
Mon, 5 Dec 2022 20:15:26 +0000 (21:15 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 18 Jan 2023 10:48:52 +0000 (11:48 +0100)
commit4b51aa263ae46ffd5720aea14e198018c43c117b
treeb9b56962d683f1e44aa1cd9500d3a9ba49af8702
parent9a8bf443f6a291d26c90db2a42dd6fe8724e72c2
usb: ulpi: defer ulpi_register on ulpi_read_id timeout

[ Upstream commit 8a7b31d545d3a15f0e6f5984ae16f0ca4fd76aac ]

Since commit 0f0101719138 ("usb: dwc3: Don't switch OTG -> peripheral
if extcon is present") Dual Role support on Intel Merrifield platform
broke due to rearranging the call to dwc3_get_extcon().

It appears to be caused by ulpi_read_id() on the first test write failing
with -ETIMEDOUT. Currently ulpi_read_id() expects to discover the phy via
DT when the test write fails and returns 0 in that case, even if DT does not
provide the phy. As a result usb probe completes without phy.

Make ulpi_read_id() return -ETIMEDOUT to its user if the first test write
fails. The user should then handle it appropriately. A follow up patch
will make dwc3_core_init() set -EPROBE_DEFER in this case and bail out.

Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT")
Cc: stable@vger.kernel.org
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Ferry Toth <ftoth@exalondelft.nl>
Link: https://lore.kernel.org/r/20221205201527.13525-2-ftoth@exalondelft.nl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/usb/common/ulpi.c