Hi,
On 04/16/2013 04:13 PM, Alan Stern wrote:
On Tue, 16 Apr 2013, Hans de Goede wrote:
When usbfs receives a ctrl-request from userspace it calls check_ctrlrecip,
which for a request with USB_RECIP_ENDPOINT tries to map this to an interface
to see if this interface is claimed, except for ctrl-requests with a type of
USB_TYPE_VENDOR.
When trying to use this device: http://www.akaipro.com/eiepro
redirected to a Windows vm running on qemu on top of Linux.
The windows driver makes a ctrl-req with USB_TYPE_CLASS and
USB_RECIP_ENDPOINT with index 0, and the mapping of the endpoint (0) to
the interface fails since ep 0 is the ctrl endpoint and thus never is
part of an interface.
This is bizarre.
Agreed, but it is really happening :|
> Why would a class specification include a class-type
request to endpoint 0 with the endpoint as the recipient? The
recipient should be the interface.
Well the device in question has both a device and interface class of 255,
so this is not an official class in anyway, yet its driver is sending
USB_TYPE_CLASS ctrl requests.
This patch fixes this ctrl-req failing by skipping the checkintf call for
USB_RECIP_ENDPOINT ctrl-reqs on the ctrl endpoint.
Reported-by: Dave Stikkolorum <d.r.stikkolorum@xxxxxx>
Tested-by: Dave Stikkolorum <d.r.stikkolorum@xxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/usb/core/devio.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 8823e98..caefc80 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -739,6 +739,8 @@ static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype,
index &= 0xff;
switch (requesttype & USB_RECIP_MASK) {
case USB_RECIP_ENDPOINT:
+ if ((index & ~USB_DIR_IN) == 0)
+ return 0;
ret = findintfep(ps->dev, index);
if (ret >= 0)
ret = checkintf(ps, ret);
Anyway, this looks fine.
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Thanks.
Regards,
Hans
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