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

[Michael Poole <mdpoole@troilus.org>]

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