From: Eldad Zack <eldad@fogrefinery.com>
To: Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@perex.cz>,
Daniel Mack <zonque@gmail.com>
Cc: alsa-devel@alsa-project.org, Eldad Zack <eldad@fogrefinery.com>
Subject: [PATCH, for-next] ALSA: usb-audio: caiaq: fix endianness bug in snd_usb_caiaq_maschine_dispatch
Date: Mon, 29 Apr 2013 21:15:46 +0200 [thread overview]
Message-ID: <1367262946-8980-1-git-send-email-eldad@fogrefinery.com> (raw)
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>
---
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);
--
1.8.1.5
next reply other threads:[~2013-04-29 19:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-29 19:15 Eldad Zack [this message]
2013-04-29 19:20 ` [PATCH, for-next] ALSA: usb-audio: caiaq: fix endianness bug in snd_usb_caiaq_maschine_dispatch Daniel Mack
2013-04-30 7:19 ` Takashi Iwai
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