drm/i915, HD-audio: Don't continue probing when nomodeset is given

When a machine is booted with nomodeset option, i915 driver skips the
whole initialization.  Meanwhile, HD-audio tries to bind wth i915 just
by request_symbol() without knowing that the initialization was
skipped, and eventually it hits WARN_ON() in i915_request_power_well()
and i915_release_power_well() wrongly but still continues probing,
even though it doesn't work at all.

In this patch, both functions are changed to return an error in case
of uninitialized state instead of WARN_ON(), so that HD-audio driver
can give up HDMI controller initialization at the right time.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: <stable@vger.kernel.org> [3.15]
Signed-off-by: Takashi Iwai <tiwai@suse.de>

3 files changed, 14 insertions, 9 deletions

diff --git a/sound/pci/hda/hda_i915.c b/sound/pci/hda/hda_i915.c
index 9d07e4ed..e9e8a4a 100644
--- a/sound/pci/hda/hda_i915.c
+++ b/sound/pci/hda/hda_i915.c
@@ -22,20 +22,20 @@
 #include <drm/i915_powerwell.h>
 #include "hda_i915.h"
 
-static void (*get_power)(void);
-static void (*put_power)(void);
+static int (*get_power)(void);
+static int (*put_power)(void);
 
-void hda_display_power(bool enable)
+int hda_display_power(bool enable)
 {
 	if (!get_power || !put_power)
-		return;
+		return -ENODEV;
 
 	pr_debug("HDA display power %s \n",
 			enable ? "Enable" : "Disable");
 	if (enable)
-		get_power();
+		return get_power();
 	else
-		put_power();
+		return put_power();
 }
 
 int hda_i915_init(void)
diff --git a/sound/pci/hda/hda_i915.h b/sound/pci/hda/hda_i915.h
index 5a63da2..bfd835f 100644
--- a/sound/pci/hda/hda_i915.h
+++ b/sound/pci/hda/hda_i915.h
@@ -17,11 +17,11 @@
 #define __SOUND_HDA_I915_H
 
 #ifdef CONFIG_SND_HDA_I915
-void hda_display_power(bool enable);
+int hda_display_power(bool enable);
 int hda_i915_init(void);
 int hda_i915_exit(void);
 #else
-static inline void hda_display_power(bool enable) {}
+static inline int hda_display_power(bool enable) { return 0; }
 static inline int hda_i915_init(void)
 {
 	return -ENODEV;
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index bb65a124..23fd6b9 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1656,8 +1656,13 @@ static int azx_probe_continue(struct azx *chip)
 				"Error request power-well from i915\n");
 			goto out_free;
 		}
+		err = hda_display_power(true);
+		if (err < 0) {
+			dev_err(chip->card->dev,
+				"Cannot turn on display power on i915\n");
+			goto out_free;
+		}
 #endif
-		hda_display_power(true);
 	}
 
 	err = azx_first_init(chip);