When usb-storage driver detects a UAS capable device, it ignores the device if CONFIG_USB_UAS is enabled. usb-storage driver assumes uas driver certainly will be loaded. However, it's possible that uas driver will not be loaded, for example, uas kernel module is not installed properly or it is in modprobe blacklist.
In case of uas driver not being loaded, the UAS capable device will not fallback to work at Bulk-only-transfer mode. The device just disappears without any notification to user/userspace. This commit changes usb-storage driver to skip UAS capable device only when uas driver is already loaded to make sure the device will at least work with Bulk protocol. Signed-off-by: JC Kuo <[email protected]> --- drivers/usb/core/driver.c | 1 + drivers/usb/storage/usb.c | 5 +++-- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index ebcadaad89d1..265c5dd490d2 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -1923,3 +1923,4 @@ struct bus_type usb_bus_type = { .uevent = usb_uevent, .need_parent_lock = true, }; +EXPORT_SYMBOL_GPL(usb_bus_type); diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index 9a79cd9762f3..d8f64e808783 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -1097,9 +1097,10 @@ static int storage_probe(struct usb_interface *intf, int result; int size; - /* If uas is enabled and this device can do uas then ignore it. */ + /* If uas driver is loaded and this device can do uas then ignore it. */ #if IS_ENABLED(CONFIG_USB_UAS) - if (uas_use_uas_driver(intf, id, NULL)) + if (driver_find("uas", &usb_bus_type) && + uas_use_uas_driver(intf, id, NULL)) return -ENXIO; #endif -- 2.17.1 ----------------------------------------------------------------------------------- This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. -----------------------------------------------------------------------------------
