[PATCH 4/6] ALSA: hda: Keep the controller initialization even if no codecs found

[Takashi Iwai]

Currently, when the HD-audio controller driver doesn't detect any
codecs, it tries to abort the probe.  But this abort happens at the
delayed probe, i.e. the primary probe call already returned success,
hence the driver is never unbound until user does so explicitly.
As a result, it may leave the HD-audio device in the running state
without the runtime PM.  More badly, if the device is a HD-audio bus
that is tied with a GPU, GPU cannot reach to the full power down and
consumes unnecessarily much power.

This patch changes the logic after no-codec situation; it continues
probing without the further codec initialization but keep the
controller driver running normally.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207043
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/pci/hda/hda_intel.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 692857904d49..aa0be85614b6 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -2009,7 +2009,7 @@ static int azx_first_init(struct azx *chip)
 	/* codec detection */
 	if (!azx_bus(chip)->codec_mask) {
 		dev_err(card->dev, "no codecs found!\n");
-		return -ENODEV;
+		/* keep running the rest for the runtime PM */
 	}
 
 	if (azx_acquire_irq(chip, 0) < 0)
@@ -2303,9 +2303,11 @@ static int azx_probe_continue(struct azx *chip)
 #endif
 
 	/* create codec instances */
-	err = azx_probe_codecs(chip, azx_max_codecs[chip->driver_type]);
-	if (err < 0)
-		goto out_free;
+	if (bus->codec_mask) {
+		err = azx_probe_codecs(chip, azx_max_codecs[chip->driver_type]);
+		if (err < 0)
+			goto out_free;
+	}
 
 #ifdef CONFIG_SND_HDA_PATCH_LOADER
 	if (chip->fw) {
@@ -2319,7 +2321,7 @@ static int azx_probe_continue(struct azx *chip)
 #endif
 	}
 #endif
-	if ((probe_only[dev] & 1) == 0) {
+	if (bus->codec_mask && !(probe_only[dev] & 1)) {
 		err = azx_codec_configure(chip);
 		if (err < 0)
 			goto out_free;
-- 
2.16.4