[PATCH 4.9 26/32] USB: Accept bulk endpoints with 1024-byte maxpacket

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

commit fb5ee84ea72c5f1b6cabdd1c9d6e8648995ca7c6 upstream.

Some non-compliant high-speed USB devices have bulk endpoints with a
1024-byte maxpacket size.  Although such endpoints don't work with
xHCI host controllers, they do work with EHCI controllers.  We used to
accept these invalid sizes (with a warning), but we no longer do
because of an unintentional change introduced by commit aed9d65ac327
("USB: validate wMaxPacketValue entries in endpoint descriptors").

This patch restores the old behavior, so that people with these
peculiar devices can use them without patching their kernels by hand.

Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Suggested-by: Elvinas <elvinas@xxxxxxxxx>
Fixes: aed9d65ac327 ("USB: validate wMaxPacketValue entries in endpoint descriptors")
CC: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/core/config.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -186,7 +186,9 @@ static const unsigned short full_speed_m
 static const unsigned short high_speed_maxpacket_maxes[4] = {
 	[USB_ENDPOINT_XFER_CONTROL] = 64,
 	[USB_ENDPOINT_XFER_ISOC] = 1024,
-	[USB_ENDPOINT_XFER_BULK] = 512,
+
+	/* Bulk should be 512, but some devices use 1024: we will warn below */
+	[USB_ENDPOINT_XFER_BULK] = 1024,
 	[USB_ENDPOINT_XFER_INT] = 1024,
 };
 static const unsigned short super_speed_maxpacket_maxes[4] = {