ALSA: hda - Avoid to set the pin control again if already set

Check the present pin control bit and avoid the write if it's already
set in patch_sigmatel.c.  This will reduce the number of verb execs at
jack plugging.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c
index 0fa6c59..11634a4 100644 (file)
--- a/sound/pci/hda/patch_sigmatel.c
+++ b/sound/pci/hda/patch_sigmatel.c
@@ -4126,7 +4126,9 @@ static void stac92xx_free(struct hda_codec *codec)
 static void stac92xx_set_pinctl(struct hda_codec *codec, hda_nid_t nid,
                                unsigned int flag)
 {
-       unsigned int pin_ctl = snd_hda_codec_read(codec, nid,
+       unsigned int old_ctl, pin_ctl;
+
+       pin_ctl = snd_hda_codec_read(codec, nid,
                        0, AC_VERB_GET_PIN_WIDGET_CONTROL, 0x00);
 
        if (pin_ctl & AC_PINCTL_IN_EN) {
@@ -4140,14 +4142,17 @@ static void stac92xx_set_pinctl(struct hda_codec *codec, hda_nid_t nid,
                        return;
        }
 
+       old_ctl = pin_ctl;
        /* if setting pin direction bits, clear the current
           direction bits first */
        if (flag & (AC_PINCTL_IN_EN | AC_PINCTL_OUT_EN))
                pin_ctl &= ~(AC_PINCTL_IN_EN | AC_PINCTL_OUT_EN);
        
-       snd_hda_codec_write_cache(codec, nid, 0,
-                       AC_VERB_SET_PIN_WIDGET_CONTROL,
-                       pin_ctl | flag);
+       pin_ctl |= flag;
+       if (old_ctl != pin_ctl)
+               snd_hda_codec_write_cache(codec, nid, 0,
+                                         AC_VERB_SET_PIN_WIDGET_CONTROL,
+                                         pin_ctl);
 }
 
 static void stac92xx_reset_pinctl(struct hda_codec *codec, hda_nid_t nid,
@@ -4155,9 +4160,10 @@ static void stac92xx_reset_pinctl(struct hda_codec *codec, hda_nid_t nid,
 {
        unsigned int pin_ctl = snd_hda_codec_read(codec, nid,
                        0, AC_VERB_GET_PIN_WIDGET_CONTROL, 0x00);
-       snd_hda_codec_write_cache(codec, nid, 0,
-                       AC_VERB_SET_PIN_WIDGET_CONTROL,
-                       pin_ctl & ~flag);
+       if (pin_ctl & flag)
+               snd_hda_codec_write_cache(codec, nid, 0,
+                                         AC_VERB_SET_PIN_WIDGET_CONTROL,
+                                         pin_ctl & ~flag);
 }
 
 static int get_pin_presence(struct hda_codec *codec, hda_nid_t nid)