diff options
| -rw-r--r-- | sound/isa/ad1848/ad1848_lib.c | 57 |
1 files changed, 21 insertions, 36 deletions
diff --git a/sound/isa/ad1848/ad1848_lib.c b/sound/isa/ad1848/ad1848_lib.c index 18355fd66cb..21536b7de60 100644 --- a/sound/isa/ad1848/ad1848_lib.c +++ b/sound/isa/ad1848/ad1848_lib.c @@ -203,9 +203,8 @@ static void snd_ad1848_mce_up(struct snd_ad1848 *chip) static void snd_ad1848_mce_down(struct snd_ad1848 *chip) { - unsigned long flags; - int timeout; - unsigned long end_time; + unsigned long flags, timeout; + int reg; spin_lock_irqsave(&chip->reg_lock, flags); for (timeout = 5; timeout > 0; timeout--) @@ -222,50 +221,36 @@ static void snd_ad1848_mce_down(struct snd_ad1848 *chip) #endif chip->mce_bit &= ~AD1848_MCE; - timeout = inb(AD1848P(chip, REGSEL)); - outb(chip->mce_bit | (timeout & 0x1f), AD1848P(chip, REGSEL)); - if (timeout == 0x80) + reg = inb(AD1848P(chip, REGSEL)); + outb(chip->mce_bit | (reg & 0x1f), AD1848P(chip, REGSEL)); + if (reg == 0x80) snd_printk(KERN_WARNING "mce_down [0x%lx]: serious init problem - codec still busy\n", chip->port); - if ((timeout & AD1848_MCE) == 0) { + if ((reg & AD1848_MCE) == 0) { spin_unlock_irqrestore(&chip->reg_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. + * It may take up to 5 sample periods (at most 907 us @ 5.5125 kHz) for + * the process to _start_, so it is important to wait at least that long + * before checking. Otherwise we might think AC has finished when it + * has in fact not begun. It could take 128 (no AC) or 384 (AC) cycles + * for ACI to drop. This gives a wait of at most 70 ms with a more + * typical value of 3-9 ms. */ - spin_unlock_irqrestore(&chip->reg_lock, flags); - msleep(1); - spin_lock_irqsave(&chip->reg_lock, flags); - - snd_printdd("(2) jiffies = %lu\n", jiffies); - - end_time = jiffies + msecs_to_jiffies(250); - while (snd_ad1848_in(chip, AD1848_TEST_INIT) & AD1848_CALIB_IN_PROGRESS) { + timeout = jiffies + msecs_to_jiffies(250); + do { spin_unlock_irqrestore(&chip->reg_lock, flags); - if (time_after(jiffies, end_time)) { - snd_printk(KERN_ERR "mce_down - auto calibration time out (2)\n"); - return; - } msleep(1); spin_lock_irqsave(&chip->reg_lock, flags); - } - - snd_printdd("(3) jiffies = %lu\n", jiffies); - - end_time = jiffies + msecs_to_jiffies(100); - while (inb(AD1848P(chip, REGSEL)) & AD1848_INIT) { - spin_unlock_irqrestore(&chip->reg_lock, flags); - if (time_after(jiffies, end_time)) { - snd_printk(KERN_ERR "mce_down - auto calibration time out (3)\n"); - return; - } - msleep(1); - spin_lock_irqsave(&chip->reg_lock, flags); - } + reg = snd_ad1848_in(chip, AD1848_TEST_INIT) & + AD1848_CALIB_IN_PROGRESS; + } while (reg && time_before(jiffies, timeout)); spin_unlock_irqrestore(&chip->reg_lock, flags); + if (reg) + snd_printk(KERN_ERR + "mce_down - auto calibration time out (2)\n"); snd_printdd("(4) jiffies = %lu\n", jiffies); snd_printd("mce_down - exit = 0x%x\n", inb(AD1848P(chip, REGSEL))); |