[ALSA] nm256: reset workaround for Latitude CSx

Modules: NM256 driver

The current snd-nm256 driver can cause Dell Latitude CSx laptops to
lock-up during module (un)load.  I have isolated this to the writes to
the control port register at offset 0x6cc which were not already
protected by the existing reset_workaround.

I tried grouping these writes with the existing reset_workaround
clause, but that caused the driver to have (un)load problems on the
Dell Latitude LS laptops.  So, I have implemented a reset_workaround_2
clause (please feel free to suggest a better name!) to cover this
situation and added a quirk entry for the CSx laptops.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 20 insertions, 3 deletions

diff --git a/sound/pci/nm256/nm256.c b/sound/pci/nm256/nm256.c
index ebfa38b5112..d0da9a53de0 100644
--- a/sound/pci/nm256/nm256.c
+++ b/sound/pci/nm256/nm256.c
@@ -62,6 +62,7 @@ static int buffer_top[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 0}; /* not spe
 static int use_cache[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 0}; /* disabled */
 static int vaio_hack[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 0}; /* disabled */
 static int reset_workaround[SNDRV_CARDS];
+static int reset_workaround_2[SNDRV_CARDS];
 
 module_param_array(index, int, NULL, 0444);
 MODULE_PARM_DESC(index, "Index value for " CARD_NAME " soundcard.");
@@ -83,6 +84,8 @@ module_param_array(vaio_hack, bool, NULL, 0444);
 MODULE_PARM_DESC(vaio_hack, "Enable workaround for Sony VAIO notebooks.");
 module_param_array(reset_workaround, bool, NULL, 0444);
 MODULE_PARM_DESC(reset_workaround, "Enable AC97 RESET workaround for some laptops.");
+module_param_array(reset_workaround_2, bool, NULL, 0444);
+MODULE_PARM_DESC(reset_workaround_2, "Enable extended AC97 RESET workaround for some other laptops.");
 
 /*
  * hw definitions
@@ -226,6 +229,7 @@ struct snd_nm256 {
         unsigned int coeffs_current: 1; /* coeff. table is loaded? */
         unsigned int use_cache: 1;      /* use one big coef. table */
         unsigned int reset_workaround: 1; /* Workaround for some laptops to avoid freeze */
+        unsigned int reset_workaround_2: 1; /* Extended workaround for some other laptops to avoid freeze */
 
         int mixer_base;                 /* register offset of ac97 mixer */
         int mixer_status_offset;        /* offset of mixer status reg. */
@@ -1199,8 +1203,11 @@ snd_nm256_ac97_reset(ac97_t *ac97)
                 /* Dell latitude LS will lock up by this */
                 snd_nm256_writeb(chip, 0x6cc, 0x87);
         }
-        snd_nm256_writeb(chip, 0x6cc, 0x80);
-        snd_nm256_writeb(chip, 0x6cc, 0x0);
+        if (! chip->reset_workaround_2) {
+                /* Dell latitude CSx will lock up by this */
+                snd_nm256_writeb(chip, 0x6cc, 0x80);
+                snd_nm256_writeb(chip, 0x6cc, 0x0);
+        }
 }
 
 /* create an ac97 mixer interface */
@@ -1536,7 +1543,7 @@ struct nm256_quirk {
         int type;
 };
 
-enum { NM_BLACKLISTED, NM_RESET_WORKAROUND };
+enum { NM_BLACKLISTED, NM_RESET_WORKAROUND, NM_RESET_WORKAROUND_2 };
 
 static struct nm256_quirk nm256_quirks[] __devinitdata = {
         /* HP omnibook 4150 has cs4232 codec internally */
@@ -1545,6 +1552,8 @@ static struct nm256_quirk nm256_quirks[] __devinitdata = {
         { .vendor = 0x104d, .device = 0x8041, .type = NM_RESET_WORKAROUND },
         /* Dell Latitude LS */
         { .vendor = 0x1028, .device = 0x0080, .type = NM_RESET_WORKAROUND },
+        /* Dell Latitude CSx */
+        { .vendor = 0x1028, .device = 0x0091, .type = NM_RESET_WORKAROUND_2 },
         { } /* terminator */
 };
 
@@ -1576,6 +1585,9 @@ static int __devinit snd_nm256_probe(struct pci_dev *pci,
                         case NM_BLACKLISTED:
                                 printk(KERN_INFO "nm256: The device is blacklisted.  Loading stopped\n");
                                 return -ENODEV;
+                        case NM_RESET_WORKAROUND_2:
+                                reset_workaround_2[dev] = 1;
+                                /* Fall-through */
                         case NM_RESET_WORKAROUND:
                                 reset_workaround[dev] = 1;
                                 break;
@@ -1632,6 +1644,11 @@ static int __devinit snd_nm256_probe(struct pci_dev *pci,
                 chip->reset_workaround = 1;
         }
 
+        if (reset_workaround_2[dev]) {
+                snd_printdd(KERN_INFO "nm256: reset_workaround_2 activated\n");
+                chip->reset_workaround_2 = 1;
+        }
+
         if ((err = snd_nm256_pcm(chip, 0)) < 0 ||
             (err = snd_nm256_mixer(chip)) < 0) {
                 snd_card_free(card);