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authorDaniel Mack <zonque@gmail.com>2012-06-12 20:23:52 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-22 11:34:16 -0700
commite3424d89f44e56186f65596725e7f28f30ab4998 (patch)
parent72211bf3b8e08f17540168bde0ab3a2f7c2658ca (diff)
USB: fix gathering of interface associations
commit b3a3dd074f7053ef824ad077e5331b52220ceba1 upstream. TEAC's UD-H01 (and probably other devices) have a gap in the interface number allocation of their descriptors: Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 220 bNumInterfaces 3 [...] Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 [...] Interface Association: bLength 8 bDescriptorType 11 bFirstInterface 2 bInterfaceCount 2 bFunctionClass 1 Audio bFunctionSubClass 0 bFunctionProtocol 32 iFunction 4 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 [...] Once a configuration is selected, usb_set_configuration() walks the known interfaces of a given configuration and calls find_iad() on each of them to set the interface association pointer the interface is included in. The problem here is that the loop variable is taken for the interface number in the comparison logic that gathers the association. Which is fine as long as the descriptors are sane. In the case above, however, the logic gets out of sync and the interface association fields of all interfaces beyond the interface number gap are wrong. Fix this by passing the interface's bInterfaceNumber to find_iad() instead. Signed-off-by: Daniel Mack <zonque@gmail.com> Reported-by: bEN <ml_all@circa.be> Reported-by: Ivan Perrone <ivanperrone@hotmail.com> Tested-by: ivan perrone <ivanperrone@hotmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 1eebd45b8137..806060ca9322 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1803,7 +1803,6 @@ free_interfaces:
intfc = cp->intf_cache[i];
intf->altsetting = intfc->altsetting;
intf->num_altsetting = intfc->num_altsetting;
- intf->intf_assoc = find_iad(dev, cp, i);
alt = usb_altnum_to_altsetting(intf, 0);
@@ -1816,6 +1815,8 @@ free_interfaces:
if (!alt)
alt = &intf->altsetting[0];
+ intf->intf_assoc =
+ find_iad(dev, cp, alt->desc.bInterfaceNumber);
intf->cur_altsetting = alt;
usb_enable_interface(dev, intf, true);
intf->dev.parent = &dev->dev;