ALSA: hdac: ext: add wait for codec to respond after link reset

As per HDA spec section 4.3 - Codec Discovery, the software shall wait
for atleast 521usec for codec to respond after link reset.
With the multi-link capability each link is turned ON/OFF individually.
Link controller drives reset signal when it is turned ON.

Signed-off-by: Rakesh Ughreja <rakesh.a.ughreja@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/hda/ext/hdac_ext_controller.c b/sound/hda/ext/hdac_ext_controller.c
index 7277411..5bc4a1d 100644 (file)
--- a/sound/hda/ext/hdac_ext_controller.c
+++ b/sound/hda/ext/hdac_ext_controller.c
@@ -271,6 +271,15 @@ int snd_hdac_ext_bus_link_get(struct hdac_bus *bus,
                }
 
                ret = snd_hdac_ext_bus_link_power_up(link);
+
+               /*
+                *  wait for 521usec for codec to report status
+                *  HDA spec section 4.3 - Codec Discovery
+                */
+               udelay(521);
+               bus->codec_mask = snd_hdac_chip_readw(bus, STATESTS);
+               dev_dbg(bus->dev, "codec_mask = 0x%lx\n", bus->codec_mask);
+               snd_hdac_chip_writew(bus, STATESTS, bus->codec_mask);
        }
 
        mutex_unlock(&bus->lock);