ALSA: hda - Allow forcibly enabling/disabling snoop

User can pass snoop option to enable/disable the snoop behavior, but
currently azx_check_snoop_available() always turns it off for some
devices.  For better debuggability, change the parameter as bint, and
allow user to enable/disable forcibly the snoop when specified via the
module option.

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

1 files changed, 18 insertions, 15 deletions

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 633020de9bd2..728663d6746f 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -196,8 +196,8 @@ MODULE_PARM_DESC(align_buffer_size,
                 "Force buffer and period sizes to be multiple of 128 bytes.");
 
 #ifdef CONFIG_X86
-static bool hda_snoop = true;
-module_param_named(snoop, hda_snoop, bool, 0444);
+static int hda_snoop = -1;
+module_param_named(snoop, hda_snoop, bint, 0444);
 MODULE_PARM_DESC(snoop, "Enable/disable snooping");
 #else
 #define hda_snoop               true
@@ -1370,29 +1370,33 @@ static void check_msi(struct azx *chip)
 /* check the snoop mode availability */
 static void azx_check_snoop_available(struct azx *chip)
 {
-        bool snoop = chip->snoop;
+        int snoop = hda_snoop;
 
+        if (snoop >= 0) {
+                dev_info(chip->card->dev, "Force to %s mode by module option\n",
+                         snoop ? "snoop" : "non-snoop");
+                chip->snoop = snoop;
+                return;
+        }
+
+        snoop = true;
         if (azx_get_snoop_type(chip) == AZX_SNOOP_TYPE_NONE &&
             chip->driver_type == AZX_DRIVER_VIA) {
                 /* force to non-snoop mode for a new VIA controller
                  * when BIOS is set
                  */
-                if (snoop) {
-                        u8 val;
-                        pci_read_config_byte(chip->pci, 0x42, &val);
-                        if (!(val & 0x80) && chip->pci->revision == 0x30)
-                                snoop = false;
-                }
+                u8 val;
+                pci_read_config_byte(chip->pci, 0x42, &val);
+                if (!(val & 0x80) && chip->pci->revision == 0x30)
+                        snoop = false;
         }
 
         if (chip->driver_caps & AZX_DCAPS_SNOOP_OFF)
                 snoop = false;
 
-        if (snoop != chip->snoop) {
-                dev_info(chip->card->dev, "Force to %s mode\n",
-                         snoop ? "snoop" : "non-snoop");
-                chip->snoop = snoop;
-        }
+        chip->snoop = snoop;
+        if (!snoop)
+                dev_info(chip->card->dev, "Force to non-snoop mode\n");
 }
 
 static void azx_probe_work(struct work_struct *work)
@@ -1452,7 +1456,6 @@ static int azx_create(struct snd_card *card, struct pci_dev *pci,
         check_probe_mask(chip, dev);
 
         chip->single_cmd = single_cmd;
-        chip->snoop = hda_snoop;
         azx_check_snoop_available(chip);
 
         if (bdl_pos_adj[dev] < 0) {