Hi Laurent,
> On 09/24/2010 05:09 PM, Laurent Pinchart wrote:
>> On 09/24/2010 04:31 PM, Laurent Pinchart wrote:
>>>> [PATCH] USB gadget: check descriptors pointer before dereferencing
>>>>
>>>> Signed-off-by: Holger Brunck <holger.brunck@xxxxxxxxxxx>
>>>> ---
>>>>
>>>> drivers/usb/gadget/composite.c | 2 +-
>>>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>>>
>>>> diff --git a/drivers/usb/gadget/composite.c
>>>> b/drivers/usb/gadget/composite.c index 09289bb..bda5cdb 100644
>>>> --- a/drivers/usb/gadget/composite.c
>>>> +++ b/drivers/usb/gadget/composite.c
>>>> @@ -436,7 +436,7 @@ static int set_config(struct usb_composite_dev
>>>> *cdev,
>>>>
>>>> else
>>>>
>>>> descriptors = f->descriptors;
>>>>
>>>> - for (; *descriptors; ++descriptors) {
>>>> + for (; descriptors && *descriptors; ++descriptors) {
>>>
>>> How comes your function has no descriptors ?
>>
>> good question and this is what confuses me. I do not understand this USB
>> code very well, but what I see is that if I skip the for loop, which
>> wasn't present in 2.6.28 my USB device is also working in 2.6.33. We added
>> some small stuff in USB to be able to configure the baudrate of the serial
>> emulation via IOCTL. But we did nothing different in the initialisation of
>> the USB device.
>>
>> The output during startup is:
>> fsl_qe_udc: Freescale QE/CPM USB Device Controller driver, 1.0
>> fsl_qe_udc f0011b60.usb: CPM USB controller initialized as device
>> g_serial gadget: Gadget Serial v2.4
>> g_serial gadget: g_serial ready
>> fsl_qe_udc f0011b60.usb: fsl_qe_udc bind to driver g_serial
>>
>> But if I plug in the connector my board is crashing without my patch.
>
> Could it be because your gadget is missing descriptors for one of the two
> speeds (FS/HS) ?
>
yes you are right. If I look at ./drivers/usb/gadget/serial.c there is no code
where these descriptors are set as e.g. in ./drivers/usb/gadget/f_serial.c
So it seems that there is an error in the initialisation of the driver than in
your code in composite.c.
Thanks for pointing out.
Regards
Holger Brunck
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