From: Eldad Zack Date: Mon, 29 Apr 2013 19:15:46 +0000 (+0200) Subject: ALSA: usb-audio: caiaq: fix endianness bug in snd_usb_caiaq_maschine_dispatch X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4ca231b2e6ed171107c5b21f9e92d1965fd6fd9e;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git 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 Signed-off-by: Eldad Zack Signed-off-by: Takashi Iwai --- diff --git a/sound/usb/caiaq/input.c b/sound/usb/caiaq/input.c index efc70ae915c5..4b3fb91deecd 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);