This is a note to let you know that I've just added the patch titled
USB: fix gathering of interface associations
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From b3a3dd074f7053ef824ad077e5331b52220ceba1 Mon Sep 17 00:00:00 2001
From: Daniel Mack <[email protected]>
Date: Tue, 12 Jun 2012 20:23:52 +0200
Subject: USB: fix gathering of interface associations
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 <[email protected]>
Reported-by: bEN <[email protected]>
Reported-by: Ivan Perrone <[email protected]>
Tested-by: ivan perrone <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/usb/core/message.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index b548cf1..bdd1c67 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1838,7 +1838,6 @@ 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);
kref_get(&intfc->ref);
alt = usb_altnum_to_altsetting(intf, 0);
@@ -1851,6 +1850,8 @@ 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;
--
1.7.10.1.362.g242cab3
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