linux-kernel - [PATCH] ALSA: HDA: Improve unlocking of a mutex in hdmi_pcm

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Date:   Wed, 15 Nov 2017 15:00:21 +0100
From:   SF Markus Elfring <elfring@...rs.sourceforge.net>
To:     alsa-devel@...a-project.org,
        Ander Conselvan De Oliveira 
        <ander.conselvan.de.oliveira@...el.com>,
        Bhumika Goyal <bhumirks@...il.com>,
        Daniel Dadap <ddadap@...dia.com>,
        Jaroslav Kysela <perex@...ex.cz>,
        Libin Yang <libin.yang@...ux.intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        "Subhransu S. Prusty" <subhransu.s.prusty@...el.com>,
        Takashi Iwai <tiwai@...e.com>,
        Vinod Koul <vinod.koul@...el.com>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        kernel-janitors@...r.kernel.org
Subject: [PATCH] ALSA: HDA: Improve unlocking of a mutex in hdmi_pcm_open()

From: Markus Elfring <elfring@...rs.sourceforge.net>
Date: Wed, 15 Nov 2017 14:46:19 +0100

* Add a jump target so that a call of the function "mutex_unlock" is stored
  only twice in this function implementation.

* Replace four calls by goto statements.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@...rs.sourceforge.net>
---
 sound/pci/hda/patch_hdmi.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index c19c81d230bd..f1c0b6cab90a 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1205,8 +1205,8 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
 	pin_idx = hinfo_to_pin_index(codec, hinfo);
 	if (!spec->dyn_pcm_assign) {
 		if (snd_BUG_ON(pin_idx < 0)) {
-			mutex_unlock(&spec->pcm_lock);
-			return -EINVAL;
+			err = -EINVAL;
+			goto unlock;
 		}
 	} else {
 		/* no pin is assigned to the PCM
@@ -1214,16 +1214,13 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
 		 */
 		if (pin_idx < 0) {
 			err = hdmi_pcm_open_no_pin(hinfo, codec, substream);
-			mutex_unlock(&spec->pcm_lock);
-			return err;
+			goto unlock;
 		}
 	}
 
 	err = hdmi_choose_cvt(codec, pin_idx, &cvt_idx);
-	if (err < 0) {
-		mutex_unlock(&spec->pcm_lock);
-		return err;
-	}
+	if (err < 0)
+		goto unlock;
 
 	per_cvt = get_cvt(spec, cvt_idx);
 	/* Claim converter */
@@ -1260,8 +1257,8 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
 			per_cvt->assigned = 0;
 			hinfo->nid = 0;
 			snd_hda_spdif_ctls_unassign(codec, pcm_idx);
-			mutex_unlock(&spec->pcm_lock);
-			return -ENODEV;
+			err = -ENODEV;
+			goto unlock;
 		}
 	}
 
@@ -1275,6 +1272,10 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
 	snd_pcm_hw_constraint_step(substream->runtime, 0,
 				   SNDRV_PCM_HW_PARAM_CHANNELS, 2);
 	return 0;
+
+unlock:
+	mutex_unlock(&spec->pcm_lock);
+	return err;
 }
 
 /*
-- 
2.15.0