> -----Original Message----- > From: Takashi Iwai [mailto:tiwai@xxxxxxx] > Sent: Tuesday, November 24, 2015 12:00 AM > To: libin.yang@xxxxxxxxxxxxxxx > Cc: alsa-devel@xxxxxxxxxxxxxxxx; mengdong.lin@xxxxxxxxxxxxxxx; Yang, > Libin > Subject: Re: [RFC V2 PATCH 3/5] ALSA: hda - hdmi > dynamically bind PCM to pin when monitor hotplug > > On Mon, 23 Nov 2015 15:09:32 +0100, > libin.yang@xxxxxxxxxxxxxxx wrote: > > > > From: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> > > > > Dynamically bind/unbind the PCM to pin when HDMI/DP monitor > hotplug. > > > > When monitor is connected, find a proper PCM for the monitor. > > When monitor is disconnected, unbind the PCM from the pin. > > You must have some strategy about binding. Please tell the story > behind the scene, too. > > > > > Signed-off-by: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> > > --- > > sound/pci/hda/patch_hdmi.c | 82 > ++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 82 insertions(+) > > > > diff --git a/sound/pci/hda/patch_hdmi.c > b/sound/pci/hda/patch_hdmi.c > > index de22ac2..bcc2a90 100644 > > --- a/sound/pci/hda/patch_hdmi.c > > +++ b/sound/pci/hda/patch_hdmi.c > > @@ -72,6 +72,8 @@ struct hdmi_spec_per_cvt { > > > > struct hdmi_spec_per_pin { > > hda_nid_t pin_nid; > > + /* pin idx, different device entries on the same pin use the same > idx */ > > + int pin_nid_idx; > > int num_mux_nids; > > hda_nid_t mux_nids[HDA_MAX_CONNECTIONS]; > > int mux_idx; > > @@ -83,6 +85,7 @@ struct hdmi_spec_per_pin { > > struct delayed_work work; > > struct snd_kcontrol *eld_ctl; > > struct hda_pcm *pcm; /* pointer to spec->pcm_rec[n] > dynamically*/ > > + int pcm_idx; /* which pcm is attached. -1 means no pcm is > attached */ > > int repoll_count; > > bool setup; /* the stream has been set up by prepare callback */ > > int channels; /* current number of channels */ > > @@ -136,6 +139,7 @@ struct hdmi_spec { > > struct snd_array pins; /* struct hdmi_spec_per_pin */ > > struct hda_pcm *pcm_rec[16]; > > struct mutex pcm_lock; > > + unsigned long pcm_bitmap; > > int pcm_used; /* counter of pcm_rec[] */ > > unsigned int channels_max; /* max over all cvts */ > > > > @@ -1663,6 +1667,70 @@ static int hdmi_read_pin_conn(struct > hda_codec *codec, int pin_idx) > > return 0; > > } > > > > +static int get_preferred_pcm_slot(struct hdmi_spec *spec, > > + struct hdmi_spec_per_pin *per_pin) > > +{ > > + if ((spec->pcm_bitmap & (1 << per_pin->pin_nid_idx)) == 0) > > Use test_bit(). Get it. > > > + return per_pin->pin_nid_idx; > > + return -1; > > +} > > + > > +static int hdmi_find_pcm_slot(struct hdmi_spec *spec, > > + struct hdmi_spec_per_pin *per_pin) > > +{ > > + int slot; > > + int i; > > + > > + /* try the prefer PCM */ > > + slot = get_preferred_pcm_slot(spec, per_pin); > > + if (slot != -1) > > + return slot; > > + > > + /* have a second try */ > > + for (i = spec->num_pins; i < spec->pcm_used; i++) { > > + if ((spec->pcm_bitmap & (1 << i)) == 0) > > Ditto. > > > + return i; > > + } > > + > > + /* the last try */ > > + for (i = 0; i < spec->pcm_used; i++) { > > + if ((spec->pcm_bitmap & (1 << i)) == 0) > > Ditto. > > > + return i; > > + } > > + return -ENODEV; > > I think you don't need to split get_preferred_pcm_slot(). > It's a function that is called only from here, and it's even better to > be open-coded. Then you can see the code flow more easily. > (Also, you may notice that the last loop doesn't go all, but just up > to num_pins, by looking through the code closely.) > > static int hdmi_find_pcm_slot(struct hdmi_spec *spec, > struct hdmi_spec_per_pin *per_pin) > { > int i; > > /* try the prefer PCM */ > if (!test_bit(per_pin->pin_nid_idx, &spec->pcm_bitmap)) > return per_pin->pin_nid_idx; > > /* have a second try; check the "reserved area" over num_pins > */ > for (i = spec->num_pins; i < spec->pcm_used; i++) > if (!test_bit(i, &spec->pcm_bitmap)) > return i; > > /* the last try; check the empty slots in pins */ > for (i = 0; i < spec->num_pins; i++) > if (!test_bit(i, &spec->pcm_bitmap)) > return i; > > return -EBUSY; > } OK. I will use the new code. Regards, Libin > > > > Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
