Hi,
On Mon, Mar 2, 2015 at 2:38 AM, Andrzej Pietrasiewicz
<andrzej.p@xxxxxxxxxxx> wrote:
> W dniu 27.02.2015 o 21:58, Felipe Balbi pisze:
>>
>> Hi,
>>
>> On Fri, Feb 27, 2015 at 02:55:25PM -0600, Felipe Balbi wrote:
>>>
>>> On Mon, Feb 23, 2015 at 04:02:09PM +0100, Andrzej Pietrasiewicz wrote:
>>>>
>>>> Non-standard requests can encode the actual interface number in a
>>>> non-standard way. For example composite_setup() assumes
>>>> that it is w_index && 0xFF, but the printer function encodes the
>>>> interface
>>>> number in a context-dependet way (either w_index or w_index >> 8).
>>>> This can lead to such requests being directed to wrong functions.
>>>>
>>>> This patch adds req_match() method to usb_function. Its purpose is to
>>>> verify that a given request can be handled by a given function.
>>>> If any function within a configuration provides the method and it
>>>> returns
>>>> true, then it is assumed that the right function is found.
>>>>
>>>> If a function uses req_match(), it should try as hard as possible to
>>>> determine if the request is meant for it.
>>>>
>>>> If no functions in a configuration provide req_match or none of them
>>>> returns true, then fall back to the usual approach.
>>>>
>>>> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
>>>
>>>
>>> this regresses testusb at least on am335x:
>>>
>
> I don't have this particular hardware but will try looking into the issue.
> As soon as I have some results I will let you know.
I am unable to explain what I found below. Toolchain related?
I added the following change to the driver.
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 07cee80..3b0e5da 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1781,6 +1781,7 @@ unknown:
break;
}
try_fun_setup:
+ dev_err(NULL, "f %p, ->setup %p\n", f, f->setup);
if (f && f->setup)
value = f->setup(f, ctrl);
else {
Then, got the following kernel crash log.
[ 59.365832] (NULL device *): f bf0116ac, ->setup 00400403
[ 59.371515] Unable to handle kernel paging request at virtual
address 00400402
So the problem is f->setup pointer is not word aligned.
The following patch seems make the issue disappeared.
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 51f477a..dde3184 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -212,10 +212,10 @@ struct usb_function {
int (*get_alt)(struct usb_function *,
unsigned interface);
void (*disable)(struct usb_function *);
- bool (*req_match)(struct usb_function *,
- const struct usb_ctrlrequest *);
int (*setup)(struct usb_function *,
const struct usb_ctrlrequest *);
+ bool (*req_match)(struct usb_function *,
+ const struct usb_ctrlrequest *);
void (*suspend)(struct usb_function *);
void (*resume)(struct usb_function *);
Regards,
-Bin.
>
> AP
>
>
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