[ALSA] ak4114 - Fix possible Oops with callbacks

ak4114 code may trigger Oops when the parameters are changed without
call of snd_ak4114_build().  Now it checks the existence of kctl
element, and the workq is triggered after building the necessary
kcontrols.
Also, did some code clean up.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 62 insertions, 33 deletions

diff --git a/sound/i2c/other/ak4114.c b/sound/i2c/other/ak4114.c
index adbfd5884d06..8f7c42c036eb 100644
--- a/sound/i2c/other/ak4114.c
+++ b/sound/i2c/other/ak4114.c
@@ -36,6 +36,7 @@ MODULE_LICENSE("GPL");
 #define AK4114_ADDR                     0x00 /* fixed address */
 
 static void ak4114_stats(struct work_struct *work);
+static void ak4114_init_regs(struct ak4114 *chip);
 
 static void reg_write(struct ak4114 *ak4114, unsigned char reg, unsigned char val)
 {
@@ -105,7 +106,7 @@ int snd_ak4114_create(struct snd_card *card,
         for (reg = 0; reg < 5; reg++)
                 chip->txcsb[reg] = txcsb[reg];
 
-        snd_ak4114_reinit(chip);
+        ak4114_init_regs(chip);
 
         chip->rcs0 = reg_read(chip, AK4114_REG_RCS0) & ~(AK4114_QINT | AK4114_CINT);
         chip->rcs1 = reg_read(chip, AK4114_REG_RCS1);
@@ -131,13 +132,10 @@ void snd_ak4114_reg_write(struct ak4114 *chip, unsigned char reg, unsigned char
                           (chip->txcsb[reg-AK4114_REG_TXCSB0] & ~mask) | val);
 }
 
-void snd_ak4114_reinit(struct ak4114 *chip)
+static void ak4114_init_regs(struct ak4114 *chip)
 {
         unsigned char old = chip->regmap[AK4114_REG_PWRDN], reg;
 
-        chip->init = 1;
-        mb();
-        flush_scheduled_work();
         /* bring the chip to reset state and powerdown state */
         reg_write(chip, AK4114_REG_PWRDN, old & ~(AK4114_RST|AK4114_PWN));
         udelay(200);
@@ -150,9 +148,18 @@ void snd_ak4114_reinit(struct ak4114 *chip)
                 reg_write(chip, reg + AK4114_REG_TXCSB0, chip->txcsb[reg]);
         /* release powerdown, everything is initialized now */
         reg_write(chip, AK4114_REG_PWRDN, old | AK4114_RST | AK4114_PWN);
+}
+
+void snd_ak4114_reinit(struct ak4114 *chip)
+{
+        chip->init = 1;
+        mb();
+        flush_scheduled_work();
+        ak4114_init_regs(chip);
         /* bring up statistics / event queing */
         chip->init = 0;
-        schedule_delayed_work(&chip->work, HZ / 10);
+        if (chip->kctls[0])
+                schedule_delayed_work(&chip->work, HZ / 10);
 }
 
 static unsigned int external_rate(unsigned char rcs1)
@@ -472,9 +479,55 @@ int snd_ak4114_build(struct ak4114 *ak4114,
                         return err;
                 ak4114->kctls[idx] = kctl;
         }
+        /* trigger workq */
+        schedule_delayed_work(&ak4114->work, HZ / 10);
         return 0;
 }
 
+/* notify kcontrols if any parameters are changed */
+static void ak4114_notify(struct ak4114 *ak4114,
+                          unsigned char rcs0, unsigned char rcs1,
+                          unsigned char c0, unsigned char c1)
+{
+        if (!ak4114->kctls[0])
+                return;
+
+        if (rcs0 & AK4114_PAR)
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[0]->id);
+        if (rcs0 & AK4114_V)
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[1]->id);
+        if (rcs1 & AK4114_CCRC)
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[2]->id);
+        if (rcs1 & AK4114_QCRC)
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[3]->id);
+
+        /* rate change */
+        if (c1 & 0xf0)
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[4]->id);
+
+        if ((c0 & AK4114_PEM) | (c0 & AK4114_CINT))
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[9]->id);
+        if (c0 & AK4114_QINT)
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[10]->id);
+
+        if (c0 & AK4114_AUDION)
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[11]->id);
+        if (c0 & AK4114_AUTO)
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[12]->id);
+        if (c0 & AK4114_DTSCD)
+                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE,
+                               &ak4114->kctls[13]->id);
+}
+
 int snd_ak4114_external_rate(struct ak4114 *ak4114)
 {
         unsigned char rcs1;
@@ -511,31 +564,7 @@ int snd_ak4114_check_rate_and_errors(struct ak4114 *ak4114, unsigned int flags)
         ak4114->rcs1 = rcs1;
         spin_unlock_irqrestore(&ak4114->lock, _flags);
 
-        if (rcs0 & AK4114_PAR)
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[0]->id);
-        if (rcs0 & AK4114_V)
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[1]->id);
-        if (rcs1 & AK4114_CCRC)
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[2]->id);
-        if (rcs1 & AK4114_QCRC)
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[3]->id);
-
-        /* rate change */
-        if (c1 & 0xf0)
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[4]->id);
-
-        if ((c0 & AK4114_PEM) | (c0 & AK4114_CINT))
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[9]->id);
-        if (c0 & AK4114_QINT)
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[10]->id);
-
-        if (c0 & AK4114_AUDION)
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[11]->id);
-        if (c0 & AK4114_AUTO)
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[12]->id);
-        if (c0 & AK4114_DTSCD)
-                snd_ctl_notify(ak4114->card, SNDRV_CTL_EVENT_MASK_VALUE, &ak4114->kctls[13]->id);
-
+        ak4114_notify(ak4114, rcs0, rcs1, c0, c1);
         if (ak4114->change_callback && (c0 | c1) != 0)
                 ak4114->change_callback(ak4114, c0, c1);
 
@@ -559,8 +588,8 @@ static void ak4114_stats(struct work_struct *work)
         struct ak4114 *chip = container_of(work, struct ak4114, work.work);
 
         if (chip->init)
-                return;
-        snd_ak4114_check_rate_and_errors(chip, 0);
+                snd_ak4114_check_rate_and_errors(chip, 0);
+
         schedule_delayed_work(&chip->work, HZ / 10);
 }