On Wed, Nov 16, 2011 at 04:29:47PM +0800, Wu, Fengguang wrote:
The Intel HDMI chips (ironlake at least) are found to have ~250ms delay between the ELD_Valid=1 hotplug event is send and the ELD buffer becomes actually readable. During the time the ELD buffer is mysteriously all 0.
Fix it by scheduling a delayed work to re-read ELD buffer after 300ms.
Just FYI.
Up to now the 300ms looks sufficient. But if ever there comes longer delays, I've already prepared a patch for retrying it for several times ;)
Thanks, Fengguang
--- sound/pci/hda/patch_hdmi.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
--- linux.orig/sound/pci/hda/patch_hdmi.c 2011-11-18 17:05:44.000000000 +0800 +++ linux/sound/pci/hda/patch_hdmi.c 2011-11-21 10:45:22.000000000 +0800 @@ -69,6 +69,7 @@ struct hdmi_spec_per_pin { struct hda_codec *codec; struct hdmi_eld sink_eld; struct delayed_work work; + int repoll_count; };
struct hdmi_spec { @@ -748,7 +749,7 @@ static void hdmi_setup_audio_infoframe(s * Unsolicited events */
-static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, bool retry); +static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll);
static void hdmi_intrinsic_event(struct hda_codec *codec, unsigned int res) { @@ -766,7 +767,7 @@ static void hdmi_intrinsic_event(struct if (pin_idx < 0) return;
- hdmi_present_sense(&spec->pins[pin_idx], true); + hdmi_present_sense(&spec->pins[pin_idx], 1); }
static void hdmi_non_intrinsic_event(struct hda_codec *codec, unsigned int res) @@ -960,7 +961,7 @@ static int hdmi_read_pin_conn(struct hda return 0; }
-static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, bool retry) +static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll) { struct hda_codec *codec = per_pin->codec; struct hdmi_eld *eld = &per_pin->sink_eld; @@ -989,10 +990,9 @@ static void hdmi_present_sense(struct hd if (eld_valid) { if (!snd_hdmi_get_eld(eld, codec, pin_nid)) snd_hdmi_show_eld(eld); - else if (retry) { + else if (repoll) { queue_delayed_work(codec->bus->workq, - &per_pin->work, - msecs_to_jiffies(300)); + &per_pin->work, repoll * HZ / 3); } }
@@ -1004,7 +1004,10 @@ static void hdmi_repoll_eld(struct work_ struct hdmi_spec_per_pin *per_pin = container_of(to_delayed_work(work), struct hdmi_spec_per_pin, work);
- hdmi_present_sense(per_pin, false); + if (per_pin->repoll_count++ > 3) + per_pin->repoll_count = 0; + + hdmi_present_sense(per_pin, per_pin->repoll_count); }
static int hdmi_add_pin(struct hda_codec *codec, hda_nid_t pin_nid) @@ -1235,7 +1238,7 @@ static int generic_hdmi_build_jack(struc if (err < 0) return err;
- hdmi_present_sense(per_pin, false); + hdmi_present_sense(per_pin, 0); return 0; }