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>

1 files changed, 2 insertions, 3 deletions

diff --git a/include/sound/hda_i915.h b/include/sound/hda_i915.h
index fa341fcb5829..f5842bcd9c94 100644
--- a/include/sound/hda_i915.h
+++ b/include/sound/hda_i915.h
@@ -9,7 +9,7 @@
 #ifdef CONFIG_SND_HDA_I915
 int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable);
 int snd_hdac_display_power(struct hdac_bus *bus, bool enable);
-int snd_hdac_get_display_clk(struct hdac_bus *bus);
+void snd_hdac_i915_set_bclk(struct hdac_bus *bus);
 int snd_hdac_sync_audio_rate(struct hdac_bus *bus, hda_nid_t nid, int rate);
 int snd_hdac_acomp_get_eld(struct hdac_bus *bus, hda_nid_t nid,
 			   bool *audio_enabled, char *buffer, int max_bytes);
@@ -25,9 +25,8 @@ static inline int snd_hdac_display_power(struct hdac_bus *bus, bool enable)
 {
 	return 0;
 }
-static inline int snd_hdac_get_display_clk(struct hdac_bus *bus)
+static inline void snd_hdac_i915_set_bclk(struct hdac_bus *bus)
 {
-	return 0;
 }
 static inline int snd_hdac_sync_audio_rate(struct hdac_bus *bus, hda_nid_t nid,
 					   int rate)