[ALSA] This simplifies and fixes waiting loops of the mce_down()

function after Trent Piepho's patch for AD1848.
It also makes busy_wait() function call not atomic.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/sound/sparc/cs4231.c b/sound/sparc/cs4231.c
index 9785382a5f39fc6b6f125adc00600eb0432cc101..f8c7a120ccbb3ce2c98821523c55223fcbbb3458 100644 (file)
--- a/sound/sparc/cs4231.c
+++ b/sound/sparc/cs4231.c
@@ -400,65 +400,44 @@ static void snd_cs4231_mce_up(struct snd_cs4231 *chip)
 
 static void snd_cs4231_mce_down(struct snd_cs4231 *chip)
 {
-       unsigned long flags;
-       unsigned long end_time;
-       int timeout;
+       unsigned long flags, timeout;
+       int reg;
 
-       spin_lock_irqsave(&chip->lock, flags);
        snd_cs4231_busy_wait(chip);
+       spin_lock_irqsave(&chip->lock, flags);
 #ifdef CONFIG_SND_DEBUG
        if (__cs4231_readb(chip, CS4231U(chip, REGSEL)) & CS4231_INIT)
                snd_printdd("mce_down [%p] - auto calibration time out (0)\n",
                            CS4231U(chip, REGSEL));
 #endif
        chip->mce_bit &= ~CS4231_MCE;
-       timeout = __cs4231_readb(chip, CS4231U(chip, REGSEL));
-       __cs4231_writeb(chip, chip->mce_bit | (timeout & 0x1f),
+       reg = __cs4231_readb(chip, CS4231U(chip, REGSEL));
+       __cs4231_writeb(chip, chip->mce_bit | (reg & 0x1f),
                        CS4231U(chip, REGSEL));
-       if (timeout == 0x80)
-               snd_printdd("mce_down [%p]: serious init problem - "
-                           "codec still busy\n",
-                           chip->port);
-       if ((timeout & CS4231_MCE) == 0) {
+       if (reg == 0x80)
+               snd_printdd("mce_down [%p]: serious init problem "
+                           "- codec still busy\n", chip->port);
+       if ((reg & CS4231_MCE) == 0) {
                spin_unlock_irqrestore(&chip->lock, flags);
                return;
        }
 
        /*
-        * Wait for (possible -- during init auto-calibration may not be set)
-        * calibration process to start. Needs upto 5 sample periods on AD1848
-        * which at the slowest possible rate of 5.5125 kHz means 907 us.
+        * Wait for auto-calibration (AC) process to finish, i.e. ACI to go low.
         */
-       msleep(1);
-
-       /* check condition up to 250ms */
-       end_time = jiffies + msecs_to_jiffies(250);
-       while (snd_cs4231_in(chip, CS4231_TEST_INIT) &
-               CS4231_CALIB_IN_PROGRESS) {
-
+       timeout = jiffies + msecs_to_jiffies(250);
+       do {
                spin_unlock_irqrestore(&chip->lock, flags);
-               if (time_after(jiffies, end_time)) {
-                       snd_printk("mce_down - "
-                                  "auto calibration time out (2)\n");
-                       return;
-               }
-               msleep(1);
-               spin_lock_irqsave(&chip->lock, flags);
-       }
-
-       /* check condition up to 100ms */
-       end_time = jiffies + msecs_to_jiffies(100);
-       while (__cs4231_readb(chip, CS4231U(chip, REGSEL)) & CS4231_INIT) {
-               spin_unlock_irqrestore(&chip->lock, flags);
-               if (time_after(jiffies, end_time)) {
-                       snd_printk("mce_down - "
-                                  "auto calibration time out (3)\n");
-                       return;
-               }
                msleep(1);
                spin_lock_irqsave(&chip->lock, flags);
-       }
+               reg = snd_cs4231_in(chip, CS4231_TEST_INIT);
+               reg &= CS4231_CALIB_IN_PROGRESS;
+       } while (reg && time_before(jiffies, timeout));
        spin_unlock_irqrestore(&chip->lock, flags);
+
+       if (reg)
+               snd_printk(KERN_ERR
+                          "mce_down - auto calibration time out (2)\n");
 }
 
 static void snd_cs4231_advance_dma(struct cs4231_dma_control *dma_cont,