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Commit 4ca231b2 authored by Eldad Zack's avatar Eldad Zack Committed by Takashi Iwai
Browse files

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: default avatarDaniel Mack <zonque@gmail.com>
Signed-off-by: default avatarEldad Zack <eldad@fogrefinery.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 167d0a11

sound/usb/caiaq/input.c

+5 −5
Original line number Diff line number Diff line
@@ -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);