ALSA: hda - Update BCLK also at hotplug for i915 HSW/BDW

The recent bug report suggests that BCLK setup for i915 HSW/BDW needs
to be updated at each HDMI hotplug, not only at initialization and
resume.  That is, we need to update HSW_EM4 and HSW_EM5 registers at
ELD notification, too.  Otherwise the HDMI audio may be out of sync
and played in a wrong pitch.

However, the HDA codec driver has no access to the controller
registers, and currently the code managing these registers is in
hda_intel.c, i.e. local to the controller driver.  For allowing the
explicit BCLK update from the codec driver, as in this patch, the
former haswell_set_bclk() in hda_intel.c is moved to hdac_i915.c and
exposed as snd_hdac_i915_set_bclk().  This is called from both the HDA
controller driver and intel_pin_eld_notify() in HDMI codec driver.

Along with this change, snd_hdac_get_display_clk() gets dropped as
it's no longer used.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91410
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 5 insertions, 52 deletions

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 637b8a0e2a91..9a0d1445ca5c 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -857,50 +857,6 @@ static int param_set_xint(const char *val, const struct kernel_param *kp)
 #define azx_del_card_list(chip) /* NOP */
 #endif /* CONFIG_PM */
 
-/* Intel HSW/BDW display HDA controller is in GPU. Both its power and link BCLK
- * depends on GPU. Two Extended Mode registers EM4 (M value) and EM5 (N Value)
- * are used to convert CDClk (Core Display Clock) to 24MHz BCLK:
- * BCLK = CDCLK * M / N
- * The values will be lost when the display power well is disabled and need to
- * be restored to avoid abnormal playback speed.
- */
-static void haswell_set_bclk(struct hda_intel *hda)
-{
-	struct azx *chip = &hda->chip;
-	int cdclk_freq;
-	unsigned int bclk_m, bclk_n;
-
-	if (!hda->need_i915_power)
-		return;
-
-	cdclk_freq = snd_hdac_get_display_clk(azx_bus(chip));
-	switch (cdclk_freq) {
-	case 337500:
-		bclk_m = 16;
-		bclk_n = 225;
-		break;
-
-	case 450000:
-	default: /* default CDCLK 450MHz */
-		bclk_m = 4;
-		bclk_n = 75;
-		break;
-
-	case 540000:
-		bclk_m = 4;
-		bclk_n = 90;
-		break;
-
-	case 675000:
-		bclk_m = 8;
-		bclk_n = 225;
-		break;
-	}
-
-	azx_writew(chip, HSW_EM4, bclk_m);
-	azx_writew(chip, HSW_EM5, bclk_n);
-}
-
 #if defined(CONFIG_PM_SLEEP) || defined(SUPPORT_VGA_SWITCHEROO)
 /*
  * power management
@@ -958,7 +914,7 @@ static int azx_resume(struct device *dev)
 	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL
 		&& hda->need_i915_power) {
 		snd_hdac_display_power(azx_bus(chip), true);
-		haswell_set_bclk(hda);
+		snd_hdac_i915_set_bclk(azx_bus(chip));
 	}
 	if (chip->msi)
 		if (pci_enable_msi(pci) < 0)
@@ -1058,7 +1014,7 @@ static int azx_runtime_resume(struct device *dev)
 		bus = azx_bus(chip);
 		if (hda->need_i915_power) {
 			snd_hdac_display_power(bus, true);
-			haswell_set_bclk(hda);
+			snd_hdac_i915_set_bclk(bus);
 		} else {
 			/* toggle codec wakeup bit for STATESTS read */
 			snd_hdac_set_codec_wakeup(bus, true);
@@ -1796,12 +1752,8 @@ static int azx_first_init(struct azx *chip)
 	/* initialize chip */
 	azx_init_pci(chip);
 
-	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) {
-		struct hda_intel *hda;
-
-		hda = container_of(chip, struct hda_intel, chip);
-		haswell_set_bclk(hda);
-	}
+	if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL)
+		snd_hdac_i915_set_bclk(bus);
 
 	hda_intel_init_chip(chip, (probe_only[dev] & 2) == 0);
 
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 40933aa33afe..1483f85999ec 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -2232,6 +2232,7 @@ static void intel_pin_eld_notify(void *audio_ptr, int port)
 	if (atomic_read(&(codec)->core.in_pm))
 		return;
 
+	snd_hdac_i915_set_bclk(&codec->bus->core);
 	check_presence_and_report(codec, pin_nid);
 }