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authorHans de Goede <hdegoede@redhat.com>2013-07-12 10:04:18 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-25 12:01:12 -0700
commit5dc50c357d5ce8f78e148d20a38e4e66b12d550f (patch)
tree14d7ff181b9f2c4c5df485953fafe1ffccf56f50 /drivers/usb/core
parentaaf6b52d50f85ed792c9c8987f5169f3dce2adea (diff)
downloadlinux-5dc50c357d5ce8f78e148d20a38e4e66b12d550f.tar.bz2
usbfs: Allow printer class 'get_device_id' without needing to claim the intf
For certain (HP) printers the printer device_id does not only contain a static part identifying the printer, but it also contains a dynamic part giving printer status, ink level, etc. To get to this info various userspace utilities need to be able to make a printer class 'get_device_id' request without first claiming the interface (as that is in use for the actual printer driver). Since the printer class 'get_device_id' request does not change interface settings in anyway, allowing this without claiming the interface should not cause any issues. CC: Sanjay Kumar <sanjay.kumar14@hp.com> CC: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/devio.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 05986507b585..737e3c19967b 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -725,15 +725,15 @@ static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype,
/*
* check for the special corner case 'get_device_id' in the printer
- * class specification, where wIndex is (interface << 8 | altsetting)
- * instead of just interface
+ * class specification, which we always want to allow as it is used
+ * to query things like ink level, etc.
*/
if (requesttype == 0xa1 && request == 0) {
alt_setting = usb_find_alt_setting(ps->dev->actconfig,
index >> 8, index & 0xff);
if (alt_setting
&& alt_setting->desc.bInterfaceClass == USB_CLASS_PRINTER)
- index >>= 8;
+ return 0;
}
index &= 0xff;