At Mon, 29 Apr 2013 21:20:43 +0200, Daniel Mack wrote:

On 29.04.2013 21:15, Eldad Zack wrote:

...

Current code does this:

be16_to_cpu(buf[i * 2] << 8 | buf[(i * 2) + 1])

Which is effectively (neglecting the index):

be16_to_cpu(be16_to_cpu(*((u16 *) buf)))

This means the int16 in the buffer is not converted at all.

Daniel Mack confirmed that the driver works on little endian CPUs, leading to the conclusion that the device-side structure is actually little endian. This changes the code to use le16_to_cpu().

Caught by sparse.

Acked-by: Daniel Mack zonque@gmail.com Signed-off-by: Eldad Zack eldad@fogrefinery.com

Appearantly, nobody (including me) has ever used the pad controls of this particular device on a BE machine. So I think it might not even be worth Cc'ing stable.

OK. Applied as is now. Thanks.

Takashi

Thanks for catching this, anyway!

Daniel

...

---

sound/usb/caiaq/input.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/sound/usb/caiaq/input.c b/sound/usb/caiaq/input.c index efc70ae..4b3fb91 100644 --- a/sound/usb/caiaq/input.c +++ b/sound/usb/caiaq/input.c @@ -488,13 +488,13 @@ static void snd_usb_caiaq_maschine_dispatch(struct snd_usb_caiaqdev *cdev, unsigned int len) { unsigned int i, pad_id;

• uint16_t pressure;

• __le16 *pressure = (__le16 *) buf;

  for (i = 0; i < MASCHINE_PADS; i++) {

• pressure = be16_to_cpu(buf[i * 2] << 8 | buf[(i * 2) + 1]);
  

• pad_id = pressure >> 12;
  

• input_report_abs(cdev->input_dev, MASCHINE_PAD(pad_id), pressure & 0xfff);
  

• pad_id = le16_to_cpu(*pressure) >> 12;
  

• input_report_abs(cdev->input_dev, MASCHINE_PAD(pad_id),
  

• 		 le16_to_cpu(*pressure) & 0xfff);
  

• pressure++;
  

  }

  input_sync(cdev->input_dev);