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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Takashi Iwai <tiwai@suse.de>,
        Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Subject: [PATCH 4.14 12/50] ALSA: hda/hdmi: Use single mutex unlock in error paths
Date:   Tue,  1 Dec 2020 09:53:11 +0100
Message-Id: <20201201084646.499434990@linuxfoundation.org>
In-Reply-To: <20201201084644.803812112@linuxfoundation.org>
References: <20201201084644.803812112@linuxfoundation.org>
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From: Takashi Iwai <tiwai@suse.de>

commit f69548ffafcc4942022f16f2f192b24143de1dba upstream

Instead of calling mutex_unlock() at each error path multiple times,
take the standard goto-and-a-single-unlock approach.  This will
simplify the code and make easier to find the unbalanced mutex locks.

No functional changes, but only the code readability improvement as a
preliminary work for further changes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 sound/pci/hda/patch_hdmi.c |   67 ++++++++++++++++++++++-----------------------
 1 file changed, 33 insertions(+), 34 deletions(-)

--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -339,13 +339,13 @@ static int hdmi_eld_ctl_info(struct snd_
 	if (!per_pin) {
 		/* no pin is bound to the pcm */
 		uinfo->count = 0;
-		mutex_unlock(&spec->pcm_lock);
-		return 0;
+		goto unlock;
 	}
 	eld = &per_pin->sink_eld;
 	uinfo->count = eld->eld_valid ? eld->eld_size : 0;
-	mutex_unlock(&spec->pcm_lock);
 
+ unlock:
+	mutex_unlock(&spec->pcm_lock);
 	return 0;
 }
 
@@ -357,6 +357,7 @@ static int hdmi_eld_ctl_get(struct snd_k
 	struct hdmi_spec_per_pin *per_pin;
 	struct hdmi_eld *eld;
 	int pcm_idx;
+	int err = 0;
 
 	pcm_idx = kcontrol->private_value;
 	mutex_lock(&spec->pcm_lock);
@@ -365,16 +366,15 @@ static int hdmi_eld_ctl_get(struct snd_k
 		/* no pin is bound to the pcm */
 		memset(ucontrol->value.bytes.data, 0,
 		       ARRAY_SIZE(ucontrol->value.bytes.data));
-		mutex_unlock(&spec->pcm_lock);
-		return 0;
+		goto unlock;
 	}
-	eld = &per_pin->sink_eld;
 
+	eld = &per_pin->sink_eld;
 	if (eld->eld_size > ARRAY_SIZE(ucontrol->value.bytes.data) ||
 	    eld->eld_size > ELD_MAX_SIZE) {
-		mutex_unlock(&spec->pcm_lock);
 		snd_BUG();
-		return -EINVAL;
+		err = -EINVAL;
+		goto unlock;
 	}
 
 	memset(ucontrol->value.bytes.data, 0,
@@ -382,9 +382,10 @@ static int hdmi_eld_ctl_get(struct snd_k
 	if (eld->eld_valid)
 		memcpy(ucontrol->value.bytes.data, eld->eld_buffer,
 		       eld->eld_size);
-	mutex_unlock(&spec->pcm_lock);
 
-	return 0;
+ unlock:
+	mutex_unlock(&spec->pcm_lock);
+	return err;
 }
 
 static const struct snd_kcontrol_new eld_bytes_ctl = {
@@ -1209,8 +1210,8 @@ static int hdmi_pcm_open(struct hda_pcm_
 	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
@@ -1218,16 +1219,13 @@ static int hdmi_pcm_open(struct hda_pcm_
 		 */
 		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 */
@@ -1264,12 +1262,11 @@ static int hdmi_pcm_open(struct hda_pcm_
 			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;
 		}
 	}
 
-	mutex_unlock(&spec->pcm_lock);
 	/* Store the updated parameters */
 	runtime->hw.channels_min = hinfo->channels_min;
 	runtime->hw.channels_max = hinfo->channels_max;
@@ -1278,7 +1275,9 @@ static int hdmi_pcm_open(struct hda_pcm_
 
 	snd_pcm_hw_constraint_step(substream->runtime, 0,
 				   SNDRV_PCM_HW_PARAM_CHANNELS, 2);
-	return 0;
+ unlock:
+	mutex_unlock(&spec->pcm_lock);
+	return err;
 }
 
 /*
@@ -1876,7 +1875,7 @@ static int generic_hdmi_playback_pcm_pre
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	bool non_pcm;
 	int pinctl;
-	int err;
+	int err = 0;
 
 	mutex_lock(&spec->pcm_lock);
 	pin_idx = hinfo_to_pin_index(codec, hinfo);
@@ -1888,13 +1887,12 @@ static int generic_hdmi_playback_pcm_pre
 		pin_cvt_fixup(codec, NULL, cvt_nid);
 		snd_hda_codec_setup_stream(codec, cvt_nid,
 					stream_tag, 0, format);
-		mutex_unlock(&spec->pcm_lock);
-		return 0;
+		goto unlock;
 	}
 
 	if (snd_BUG_ON(pin_idx < 0)) {
-		mutex_unlock(&spec->pcm_lock);
-		return -EINVAL;
+		err = -EINVAL;
+		goto unlock;
 	}
 	per_pin = get_pin(spec, pin_idx);
 	pin_nid = per_pin->pin_nid;
@@ -1933,6 +1931,7 @@ static int generic_hdmi_playback_pcm_pre
 	/* snd_hda_set_dev_select() has been called before */
 	err = spec->ops.setup_stream(codec, cvt_nid, pin_nid,
 				 stream_tag, format);
+ unlock:
 	mutex_unlock(&spec->pcm_lock);
 	return err;
 }
@@ -1954,6 +1953,7 @@ static int hdmi_pcm_close(struct hda_pcm
 	struct hdmi_spec_per_cvt *per_cvt;
 	struct hdmi_spec_per_pin *per_pin;
 	int pinctl;
+	int err = 0;
 
 	if (hinfo->nid) {
 		pcm_idx = hinfo_to_pcm_index(codec, hinfo);
@@ -1972,14 +1972,12 @@ static int hdmi_pcm_close(struct hda_pcm
 		snd_hda_spdif_ctls_unassign(codec, pcm_idx);
 		clear_bit(pcm_idx, &spec->pcm_in_use);
 		pin_idx = hinfo_to_pin_index(codec, hinfo);
-		if (spec->dyn_pcm_assign && pin_idx < 0) {
-			mutex_unlock(&spec->pcm_lock);
-			return 0;
-		}
+		if (spec->dyn_pcm_assign && pin_idx < 0)
+			goto unlock;
 
 		if (snd_BUG_ON(pin_idx < 0)) {
-			mutex_unlock(&spec->pcm_lock);
-			return -EINVAL;
+			err = -EINVAL;
+			goto unlock;
 		}
 		per_pin = get_pin(spec, pin_idx);
 
@@ -1998,10 +1996,11 @@ static int hdmi_pcm_close(struct hda_pcm
 		per_pin->setup = false;
 		per_pin->channels = 0;
 		mutex_unlock(&per_pin->lock);
+	unlock:
 		mutex_unlock(&spec->pcm_lock);
 	}
 
-	return 0;
+	return err;
 }
 
 static const struct hda_pcm_ops generic_ops = {