Commit Graph

2 Commits

Author SHA1 Message Date
Wei Yongjun 97eba3260e usb: roles: Fix return value check in intel_xhci_usb_probe()
In case of error, the function devm_ioremap_nocache() returns NULL
pointer not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.

Fixes: f6fb9ec02b ("usb: roles: Add Intel xHCI USB role switch driver")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-26 11:59:25 +02:00
Hans de Goede f6fb9ec02b usb: roles: Add Intel xHCI USB role switch driver
Various Intel SoCs (Cherry Trail, Broxton and others) have an internal USB
role switch for swiching the OTG USB data lines between the xHCI host
controller and the dwc3 gadget controller.

Note on some Cherry Trail systems there is ACPI/AML code listening to
edge interrupts on the id-pin (through an _AIE ACPI method) and switching
the role between ROLE_HOST and ROLE_NONE based on the id-pin. Note it does
not set the role to ROLE_DEVICE, because device-mode is usually not used
under Windows.

The presence of AML code which modifies the cfg0 reg (on some systems)
means that our read/write/modify of cfg0 may race with the AML code
doing the same to avoid this we take the global ACPI lock while doing
the read/write/modify.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22 13:49:27 +01:00