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ALSA: usb-audio: caiaq: fix endianness bug in snd_usb_caiaq_maschine_dispatch 

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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Eldad Zack 2013-04-29 21:15:46 +02:00 committed by Takashi Iwai
parent 167d0a11d5
commit 4ca231b2e6
1 changed files with 5 additions and 5 deletions
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10
sound/usb/caiaq/input.c
View File

@ -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);