[alsa-devel] [PATCH] cs4231-lib: improved waiting after mce_down (2nd rev)

[Takashi Iwai]

At Tue, 11 Sep 2007 01:08:07 +0200,
I wrote:
> 
> At Tue, 11 Sep 2007 00:43:42 +0200,
> Rene Herman wrote:
> > 
> > Second -- not schedule_timeout_interruptible? A plain schedule_timeout won't 
> > work, as you first need to __set_current_state or it will not schedule. That 
> > is, schedule_timeout_interruptible or _uniterruptible and with the latter, 
> > the loop wouldn't make much sense anymore as it's just going to sleep for 
> > the full 250 ms directly.
> 
> Ah, right.  I'm obviously too sleepy to review now...
> 
> Actually, the code with msleep() was basically OK.  If more finer
> check is needed, it can simply use msleep(1).  The point is to use
> timer_after_eq() instead of loop count for the precise timeouts.

Could you check whether the below patch works?


Takashi

diff -r 475132691bb1 isa/cs423x/cs4231_lib.c
--- a/isa/cs423x/cs4231_lib.c	Tue Sep 11 00:55:46 2007 +0200
+++ b/isa/cs423x/cs4231_lib.c	Tue Sep 11 01:15:17 2007 +0200
@@ -313,6 +313,7 @@ void snd_cs4231_mce_down(struct snd_cs42
 void snd_cs4231_mce_down(struct snd_cs4231 *chip)
 {
 	unsigned long flags;
+	unsigned long end_time;
 	int timeout;
 
 	snd_cs4231_busy_wait(chip);
@@ -344,28 +345,28 @@ void snd_cs4231_mce_down(struct snd_cs42
 	snd_printdd("(1) jiffies = %lu\n", jiffies);
 
 	/* check condition up to 250 ms */
-	timeout = msecs_to_jiffies(250);
+	end_time = jiffies + msecs_to_jiffies(250);
 	while (snd_cs4231_in(chip, CS4231_TEST_INIT) &
 		CS4231_CALIB_IN_PROGRESS) {
 
-		if (timeout <= 0) {
+		if (time_after(jiffies, end_time)) {
 			snd_printk(KERN_ERR "mce_down - "
 					"auto calibration time out (2)\n");
 			return;
 		}
-		timeout = schedule_timeout(timeout);
+		msleep(1);
 	}
 
 	snd_printdd("(2) jiffies = %lu\n", jiffies);
 
 	/* check condition up to 100 ms */
-	timeout = msecs_to_jiffies(100);
+	end_time = jiffies + msecs_to_jiffies(100);
 	while (cs4231_inb(chip, CS4231P(REGSEL)) & CS4231_INIT) {
-		if (timeout <= 0) {
+		if (time_after(jiffies, end_time)) {
 			snd_printk(KERN_ERR "mce_down - auto calibration time out (3)\n");
 			return;
 		}
-		timeout = schedule_timeout(timeout);
+		msleep(1);
 	}
 
 	snd_printdd("(3) jiffies = %lu\n", jiffies);
diff -r 475132691bb1 sparc/cs4231.c
--- a/sparc/cs4231.c	Tue Sep 11 00:55:46 2007 +0200
+++ b/sparc/cs4231.c	Tue Sep 11 01:15:17 2007 +0200
@@ -401,6 +401,7 @@ static void snd_cs4231_mce_down(struct s
 static void snd_cs4231_mce_down(struct snd_cs4231 *chip)
 {
 	unsigned long flags;
+	unsigned long end_time;
 	int timeout;
 
 	spin_lock_irqsave(&chip->lock, flags);
@@ -431,30 +432,30 @@ static void snd_cs4231_mce_down(struct s
 	msleep(1);
 
 	/* check condition up to 250ms */
-	timeout = msecs_to_jiffies(250);
+	end_time = jiffies + msecs_to_jiffies(250);
 	while (snd_cs4231_in(chip, CS4231_TEST_INIT) &
 		CS4231_CALIB_IN_PROGRESS) {
 
 		spin_unlock_irqrestore(&chip->lock, flags);
-		if (timeout <= 0) {
+		if (time_after(jiffies, end_time)) {
 			snd_printk("mce_down - "
 				   "auto calibration time out (2)\n");
 			return;
 		}
-		timeout = schedule_timeout(timeout);
+		msleep(1);
 		spin_lock_irqsave(&chip->lock, flags);
 	}
 
 	/* check condition up to 100ms */
-	timeout = msecs_to_jiffies(100);
+	end_time = jiffies + msecs_to_jiffies(100);
 	while (__cs4231_readb(chip, CS4231U(chip, REGSEL)) & CS4231_INIT) {
 		spin_unlock_irqrestore(&chip->lock, flags);
-		if (timeout <= 0) {
+		if (time_after(jiffies, end_time)) {
 			snd_printk("mce_down - "
 				   "auto calibration time out (3)\n");
 			return;
 		}
-		timeout = schedule_timeout(timeout);
+		msleep(1);
 		spin_lock_irqsave(&chip->lock, flags);
 	}
 	spin_unlock_irqrestore(&chip->lock, flags);