Hi! Usb devio assumes that the wIndex in every control message apart from those flagged as USB_TYPE_VENDOR holds the number of the Interface being addressed. This is for example not true for the class specific request GET_DEVICE_ID in the printer class: "The high-byte of the wIndex field is used to specify the zero-based interface index. The low-byte of the wIndex field is used to specify the zero-based alternate setting." [1] In this special case it misinterpretes the alternate setting 1 for the interface and tries to claim a nonexisting one. Therefor you won't get the printers name. The patch below is a minimal approach to fix this. Maybe it should be extended to USB_TYPE_RESERVED. Maybe there should be an extended test that knows something about specific classes. What do you think? regards Matthias [1] http://www.usb.org/developers/devclass_docs/usbprint11.pdf >From 724e3b5e8782a584a95d05bb2f44e59743ed3a72 Mon Sep 17 00:00:00 2001 From: Matthias Dellweg <2500@xxxxxx> Date: Wed, 21 Sep 2011 21:28:18 +0200 Subject: [PATCH] drivers/usb/core/devio.c: Relax test in check_ctrlrecip The generic test for the interface is not valid when the request type is class specific. Signed-off-by: Matthias Dellweg <2500@xxxxxx> --- drivers/usb/core/devio.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 37518df..4e78768 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -615,7 +615,8 @@ static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype, && ps->dev->state != USB_STATE_ADDRESS && ps->dev->state != USB_STATE_CONFIGURED) return -EHOSTUNREACH; - if (USB_TYPE_VENDOR == (USB_TYPE_MASK & requesttype)) + if ((USB_TYPE_VENDOR == (USB_TYPE_MASK & requesttype)) + || (USB_TYPE_CLASS == (USB_TYPE_MASK & requesttype))) return 0; index &= 0xff; -- 1.7.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
