[PATCH 3.16 256/366] USB: Accept bulk endpoints with 1024-byte maxpacket

Ben Hutchings
2018-10-14T23:12:05Z

From: Alan Stern <stern@rowland.harvard.edu>

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@rowland.harvard.edu>
Suggested-by: Elvinas <elvinas@veikia.lt>
Fixes: aed9d65ac327 ("USB: validate wMaxPacketValue entries in endpoint descriptors")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
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
@@ -157,7 +157,9 @@ 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] = {