Reading bEndpointAddress the spec tells is
that
b7 is direction, which must be ignored
b6:4 are reserved which are to be set to zero
b3:0 are the endpoint address
In order to be backwards compatible with possible
future versions of USB we have to be ready with
devices using those bits. That means that we
also have to ignore them like we do with the direction
bit.
In consequence the only illegal address you can
encoding in four bits is endpoint zero, for which
no descriptor must exist. Hence the check for exceeding
the upper limit on endpoint addresses is removed.
Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
V2: Improved commit log
---
drivers/usb/core/config.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 8fd4208d17db..43c5ed256e6e 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -285,11 +285,11 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno,
goto skip_to_next_endpoint_or_interface_descriptor;
}
- i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
- if (i >= 16 || i == 0) {
+ i = d->bEndpointAddress & 0x0f;
+ if (i == 0) {
dev_notice(ddev, "config %d interface %d altsetting %d has an "
- "invalid endpoint with address 0x%X, skipping\n",
- cfgno, inum, asnum, d->bEndpointAddress);
+ "invalid descriptor for the common control endpoint, skipping\n",
+ cfgno, inum, asnum);
goto skip_to_next_endpoint_or_interface_descriptor;
}
--
2.44.0
