linux-kernel - [PATCH] [media] em28xx: calculate left volume level correctly

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Message-Id: <20170822142120.14348-1-colin.king@canonical.com>
Date:   Tue, 22 Aug 2017 15:21:20 +0100
From:   Colin King <colin.king@...onical.com>
To:     Mauro Carvalho Chehab <mchehab@...nel.org>,
        linux-media@...r.kernel.org
Cc:     kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] [media] em28xx: calculate left volume level correctly

From: Colin Ian King <colin.king@...onical.com>

The calculation of the left volume looks suspect, the value of
0x1f - ((val << 8) & 0x1f) is always 0x1f. The debug prior to the
assignemnt of value[1] prints the left volume setting using the
calculation 0x1f - (val >> 8) & 0x1f which looks correct to me.
Fix the left volume by using the correct expression as used in
the debug.

Detected by CoverityScan, CID#146140 ("Wrong operator used")

Fixes: 850d24a5a861 ("[media] em28xx-alsa: add mixer support for AC97 volume controls")
Signed-off-by: Colin Ian King <colin.king@...onical.com>
---
 drivers/media/usb/em28xx/em28xx-audio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c
index 261620a57420..4628d73f46f2 100644
--- a/drivers/media/usb/em28xx/em28xx-audio.c
+++ b/drivers/media/usb/em28xx/em28xx-audio.c
@@ -564,7 +564,7 @@ static int em28xx_vol_get(struct snd_kcontrol *kcontrol,
 		val, (int)kcontrol->private_value);
 
 	value->value.integer.value[0] = 0x1f - (val & 0x1f);
-	value->value.integer.value[1] = 0x1f - ((val << 8) & 0x1f);
+	value->value.integer.value[1] = 0x1f - ((val >> 8) & 0x1f);
 
 	return 0;
 }
-- 
2.14.1