Re: [PATCH 0/3] HID: make raw output callback more flexible

Michael Poole
2010-01-31T03:27:48Z

Bastien Nocera writes:

> On Fri, 2010-01-29 at 19:46 -0500, Michael Poole wrote:
>> > [1]: Comments on the patch at
>> > http://thread.gmane.org/gmane.linux.bluez.kernel/4279 would be
>> > appreciated
>>
>> This patch does not work for me. Before, the first time after each
>> boot
>> that I tried to connect to an Apple Magic Mouse, it failed with -14
>> (EFAULT). With this patch, it fails with -22 (EINVAL) instead. The
>> -EFAULT *was* due to hidp_parse()'s copy_from_user(). I have not
>> looked
>> yet to see where the -EINVAL is coming from -- would that help? (Both
>> with and without your patch, the second attempt to connect works.)
>
> I don't get -EFAULT anymore (it was failing to copy the rd_data from
> user-space), but I do get -EINVALs now. I haven't investigated it
> though. My guess is that the hid parser fails.
>
> Could you compare the sizes of the data gathered in user-space?

It looks like something else is overwriting parts of the hidp_session
structure; I hope to find out what that is tomorrow. Based on a
printk() in hidp_sock_ioctl(), user space consistently passes a 99-byte
HID report descriptor. I added another printk() to hidp_parse() to
characterize things:
printk("hidp_parse(%p): %u@%p\n", hid, req->rd_size, req->rd_data);

With your patch, the first time I connect to the mouse:
[ 244.109619] hidp_parse(ffff880138f90000): 0@0000002800000000
[ 244.109694] magicmouse 0005:05AC:030D.0001: magicmouse hid parse
failed
[ 244.109708] magicmouse: probe of 0005:05AC:030D.0001 failed with
error -22

With your patch, the second time:
[ 258.840542] hidp_parse(ffff880134e14000): 99@ffff88008fd8f880
[ 258.841415] input: Apple Wireless Mouse as
/devices/pci0000:00/0000:00:1d.2/usb8/8-1/8-1:1.0/bluetooth/hci0/hci0:12/input11

Without your patch, the first time:
[ 157.569000] hidp_parse(ffff8801313cc000): 11859@ffffffff811397c0
[ 157.569018] magicmouse 0005:05AC:030D.0001: magicmouse hid parse
failed
[ 157.569031] magicmouse: probe of 0005:05AC:030D.0001 failed with
error -14

Without your patch, the second time:
[ 178.983956] hidp_parse(ffff88012e660000): 99@00007f40d7d44880
[ 178.984977] input: Apple Wireless Mouse as
/devices/pci0000:00/0000:00:1d.2/usb8/8-1/8-1:1.0/bluetooth/hci0/hci0:12/input11

Michael Poole