ALSA: hda-intel - add special 'hwio' model to bypass initialization

Using the 'model=hwio' option, the driver bypasses any codec
initialization and the reset procedure for codecs is also
bypassed. This mode is usefull to enable direct access using
hwdep interface (using hdaverb or hda-analyzer tools) and
retain codec setup from BIOS.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

1 files changed, 12 insertions, 8 deletions

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 8b2915631cc3..8d477613bccf 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -858,10 +858,13 @@ static void azx_power_notify(struct hda_bus *bus);
 #endif
 
 /* reset codec link */
-static int azx_reset(struct azx *chip)
+static int azx_reset(struct azx *chip, int full_reset)
 {
         int count;
 
+        if (!full_reset)
+                goto __skip;
+
         /* clear STATESTS */
         azx_writeb(chip, STATESTS, STATESTS_INT_MASK);
 
@@ -887,6 +890,7 @@ static int azx_reset(struct azx *chip)
         /* Brent Chartrand said to wait >= 540us for codecs to initialize */
         msleep(1);
 
+      __skip:
         /* check to see if controller is ready */
         if (!azx_readb(chip, GCTL)) {
                 snd_printd(SFX "azx_reset: controller not ready!\n");
@@ -998,13 +1002,13 @@ static void azx_stream_stop(struct azx *chip, struct azx_dev *azx_dev)
 /*
  * reset and start the controller registers
  */
-static void azx_init_chip(struct azx *chip)
+static void azx_init_chip(struct azx *chip, int full_reset)
 {
         if (chip->initialized)
                 return;
 
         /* reset controller */
-        azx_reset(chip);
+        azx_reset(chip, full_reset);
 
         /* initialize interrupts */
         azx_int_clear(chip);
@@ -1348,7 +1352,7 @@ static void azx_bus_reset(struct hda_bus *bus)
 
         bus->in_reset = 1;
         azx_stop_chip(chip);
-        azx_init_chip(chip);
+        azx_init_chip(chip, 1);
 #ifdef CONFIG_PM
         if (chip->initialized) {
                 int i;
@@ -1422,7 +1426,7 @@ static int __devinit azx_codec_create(struct azx *chip, const char *model)
                                  * get back to the sanity state.
                                  */
                                 azx_stop_chip(chip);
-                                azx_init_chip(chip);
+                                azx_init_chip(chip, 1);
                         }
                 }
         }
@@ -2112,7 +2116,7 @@ static void azx_power_notify(struct hda_bus *bus)
                 }
         }
         if (power_on)
-                azx_init_chip(chip);
+                azx_init_chip(chip, 1);
         else if (chip->running && power_save_controller &&
                  !bus->power_keep_link_on)
                 azx_stop_chip(chip);
@@ -2182,7 +2186,7 @@ static int azx_resume(struct pci_dev *pci)
         azx_init_pci(chip);
 
         if (snd_hda_codecs_inuse(chip->bus))
-                azx_init_chip(chip);
+                azx_init_chip(chip, 1);
 
         snd_hda_resume(chip->bus);
         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
@@ -2573,7 +2577,7 @@ static int __devinit azx_create(struct snd_card *card, struct pci_dev *pci,
 
         /* initialize chip */
         azx_init_pci(chip);
-        azx_init_chip(chip);
+        azx_init_chip(chip, model[dev] == NULL || strcmp(model[dev], "hwio"));
 
         /* codec detection */
         if (!chip->codec_mask) {