linux-kernel - [PATCH] ALSA: hda/tegra: enable clock during probe

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Message-ID: <1548351403-1875-1-git-send-email-spujar@nvidia.com>
Date:   Thu, 24 Jan 2019 23:06:43 +0530
From:   Sameer Pujar <spujar@...dia.com>
To:     <perex@...ex.cz>, <tiwai@...e.com>,
        <pierre-louis.bossart@...ux.intel.com>
CC:     <thierry.reding@...il.com>, <jonathanh@...dia.com>,
        <rlokhande@...dia.com>, <alsa-devel@...a-project.org>,
        <linux-tegra@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        Sameer Pujar <spujar@...dia.com>
Subject: [PATCH] ALSA: hda/tegra: enable clock during probe

If CONFIG_PM is disabled or runtime PM calls are forbidden, the clocks
will not be ON. This could cause issue during probe, where hda init
setup is done. This patch checks whether runtime PM is enabled or not.
If disabled, clocks are enabled in probe() and disabled in remove()

This patch does following minor changes as cleanup,
  * return code check for pm_runtime_get_sync() to take care of failure
    and exit gracefully.
  * In remove path runtime PM is disabled before calling snd_card_free().
  * hda_tegra_disable_clocks() is moved out of CONFIG_PM_SLEEP check.
  * runtime PM callbacks moved out of CONFIG_PM check

Signed-off-by: Sameer Pujar <spujar@...dia.com>
Reviewed-by: Ravindra Lokhande <rlokhande@...dia.com>
Reviewed-by: Jon Hunter <jonathanh@...dia.com>
---
 sound/pci/hda/hda_tegra.c | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c
index c8d18dc..155c2f5 100644
--- a/sound/pci/hda/hda_tegra.c
+++ b/sound/pci/hda/hda_tegra.c
@@ -219,7 +219,6 @@ static int hda_tegra_enable_clocks(struct hda_tegra *data)
 	return rc;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static void hda_tegra_disable_clocks(struct hda_tegra *data)
 {
 	clk_disable_unprepare(data->hda2hdmi_clk);
@@ -227,6 +226,7 @@ static void hda_tegra_disable_clocks(struct hda_tegra *data)
 	clk_disable_unprepare(data->hda_clk);
 }
 
+#ifdef CONFIG_PM_SLEEP
 /*
  * power management
  */
@@ -257,7 +257,6 @@ static int hda_tegra_resume(struct device *dev)
 }
 #endif /* CONFIG_PM_SLEEP */
 
-#ifdef CONFIG_PM
 static int hda_tegra_runtime_suspend(struct device *dev)
 {
 	struct snd_card *card = dev_get_drvdata(dev);
@@ -283,7 +282,7 @@ static int hda_tegra_runtime_resume(struct device *dev)
 	int rc;
 
 	rc = hda_tegra_enable_clocks(hda);
-	if (rc != 0)
+	if (rc)
 		return rc;
 	if (chip && chip->running) {
 		hda_tegra_init(hda);
@@ -292,7 +291,6 @@ static int hda_tegra_runtime_resume(struct device *dev)
 
 	return 0;
 }
-#endif /* CONFIG_PM */
 
 static const struct dev_pm_ops hda_tegra_pm = {
 	SET_SYSTEM_SLEEP_PM_OPS(hda_tegra_suspend, hda_tegra_resume)
@@ -555,6 +553,13 @@ static int hda_tegra_probe(struct platform_device *pdev)
 	if (!azx_has_pm_runtime(chip))
 		pm_runtime_forbid(hda->dev);
 
+	/* explicit resume if runtime PM is disabled */
+	if (!pm_runtime_enabled(hda->dev)) {
+		err = hda_tegra_runtime_resume(hda->dev);
+		if (err)
+			goto out_free;
+	}
+
 	schedule_work(&hda->probe_work);
 
 	return 0;
@@ -571,7 +576,14 @@ static void hda_tegra_probe_work(struct work_struct *work)
 	struct platform_device *pdev = to_platform_device(hda->dev);
 	int err;
 
-	pm_runtime_get_sync(hda->dev);
+	err = pm_runtime_get_sync(hda->dev);
+	if (err < 0) {
+		dev_err(hda->dev,
+			"failed in pm_runtime_get_syc with err = %d\n",
+			err);
+		return;
+	}
+
 	err = hda_tegra_first_init(chip, pdev);
 	if (err < 0)
 		goto out_free;
@@ -599,12 +611,13 @@ static void hda_tegra_probe_work(struct work_struct *work)
 
 static int hda_tegra_remove(struct platform_device *pdev)
 {
-	int ret;
-
-	ret = snd_card_free(dev_get_drvdata(&pdev->dev));
 	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev)) {
+		hda_tegra_runtime_suspend(&pdev->dev);
+		pm_runtime_set_suspended(&pdev->dev);
+	}
 
-	return ret;
+	return snd_card_free(dev_get_drvdata(&pdev->dev));
 }
 
 static void hda_tegra_shutdown(struct platform_device *pdev)
-- 
2.7.4