Re: [PATCH] Wait for all codecs to be ready if doing a cold reset

[Takashi Iwai <tiwai@suse.de>]

At Wed, 9 Jul 2008 14:26:38 -0300,
Thadeu Lima de Souza Cascardo wrote:
> 
> On Wed, Jul 09, 2008 at 08:23:12PM +0200, Takashi Iwai wrote:
> > At Tue, 8 Jul 2008 14:31:22 -0300,
> > Thadeu Lima de Souza Cascardo wrote:
> > > 
> > > On Wed, Jul 09, 2008 at 05:07:17PM +0200, Takashi Iwai wrote:
> > > > At Tue, 8 Jul 2008 13:59:32 -0300,
> > > > Thadeu Lima de Souza Cascardo wrote:
> > > > > 
> > > > > On Tue, Jul 08, 2008 at 12:16:35PM +0200, Takashi Iwai wrote:
> > > > > > At Mon, 7 Jul 2008 14:36:55 -0300,
> > > > > > Thadeu Lima de Souza Cascardo wrote:
> > > > > > > 
> > > > > > > On Mon, Jul 07, 2008 at 06:39:09PM +0200, Takashi Iwai wrote:
> > > > > > > > At Sun, 6 Jul 2008 14:15:56 -0300,
> > > > > > > > Thadeu Lima de Souza Cascardo wrote:
> > > > > > > > > 
> > > > > > > > > If AC97_POWER_SAVE is enabled, intel8x0 does a cold reset when
> > > > > > > > > initializing the codecs. While resuming, it does not wait for all codecs
> > > > > > > > > to be active. Sound card does not work after a resume without it,
> > > > > > > > > however. This patch fixes it.
> > > > > > > > 
> > > > > > > > Thanks for the patch.
> > > > > > > > 
> > > > > > > > But, I still don't figure out why this is needed.
> > > > > > > > In the else block (with the comment "resume phase"), you can find the
> > > > > > > > loop to wait for the all *probed* codecs.  The difference with the
> > > > > > > > code you moved is that it checks only the bits corresponding to the
> > > > > > > > already probed codecs.  In other words, the other bits should be
> > > > > > > > irrelevant with the hardware.
> > > > > > > > 
> > > > > > > > I guess it's not about the loop but the additional 1/4 sec delay that
> > > > > > > > did fix the resume on your device.  Please check how is the status
> > > > > > > > bits and whether it passed the loop in the middle.
> > > > > > > > 
> > > > > > > > 
> > > > > > > > Takashi
> > > > > > > > 
> > > > > > > > 
> > > > > > > 
> > > > > > > The 1/4 sec delay came in my mind as one of the possible reasons, and
> > > > > > > that's why I've made some tests. status and nstatus are 0x200, while
> > > > > > > codec_isr_bits is 0x300. The loop waits for the status register give us
> > > > > > > 0x300 as the active codecs, instead of the only one probed. Since the
> > > > > > > cold reset in the case of a power saving cleans up all codec registers,
> > > > > > > it is needed that we wait for all codecs again (like in the probe case).
> > > > > > 
> > > > > > You loaded the modem driver as well?
> > > > > > If so, what happens if you unload modem driver?
> > > > > > 
> > > > > > 
> > > > > > thanks,
> > > > > > 
> > > > > > Takashi
> > > > > > 
> > > > > 
> > > > > The modem driver has always been loaded. Unloading it with my patch
> > > > > works OK.
> > > > 
> > > > Well, I meant to unload the modem driver *without* your patch.
> > > > That is, does it the unmodified version work if you unload the modem
> > > > driver beforehand (e.g. adding it to blacklist)?
> > > > 
> > > > 
> > > > thanks,
> > > > 
> > > > Takashi
> > > > 
> > > 
> > > I blacklisted snd_intel8x0m, rebooted, it was not loaded, sound worked.
> > > Suspended, resumed, sound didn't work, as usual.
> > 
> > Thanks for checking.
> > 
> > I still don't understand why you need to wait for all codecs.
> > Certainly the secondary one is the modem codec, and it has nothing to
> > do with the audio codec...
> > 
> > I don't mind to apply the patch as is since it's harmless except for
> > the extra delay.  But, the real question is whether it's the codec
> > probe or just another delay.
> > 
> > Note that not all devices have codecs filling all slots like yours.
> > On the later ICH, it has three slots while usually two of them are
> > used.  So, on these hardwares, your code results always in just a 25ms
> > delay.
> > 
> > Anyway, could you give your sign-off?
> > 
> > 
> > thanks,
> > 
> > Takashi
> 
> 
> Maybe we could treat this as a quirk in my device, which is 8086:2485?
> 
> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@minaslivre.org>

Thanks.

Meanwhile, I reconsidered about this problem.  I think the check of
the whole "active" codec slots can be done better in a way like the
following.  Could you give it a try?

If this still doesn't work, I suspect it's really the matter of
additional delay.


thanks,

Takashi
---
diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c
index 048d99e..a282c7c 100644
--- a/sound/pci/intel8x0.c
+++ b/sound/pci/intel8x0.c
@@ -404,6 +404,7 @@ struct intel8x0 {
 	unsigned int *codec_bit;
 	unsigned int codec_isr_bits;
 	unsigned int codec_ready_bits;
+	unsigned int codec_init_bits;
 
 	spinlock_t reg_lock;
 	
@@ -2278,7 +2279,7 @@ static void do_ali_reset(struct intel8x0 *chip)
 static int snd_intel8x0_ich_chip_init(struct intel8x0 *chip, int probing)
 {
 	unsigned long end_time;
-	unsigned int cnt, status, nstatus;
+	unsigned int cnt, status;
 	
 	/* put logic to right state */
 	/* first clear status bits */
@@ -2344,20 +2345,15 @@ static int snd_intel8x0_ich_chip_init(struct intel8x0 *chip, int probing)
 			status |= igetdword(chip, ICHREG(GLOB_STA)) &
 				chip->codec_isr_bits;
 		}
-
+		chip->codec_init_bits = status;
 	} else {
 		/* resume phase */
-		int i;
-		status = 0;
-		for (i = 0; i < chip->ncodecs; i++)
-			if (chip->ac97[i])
-				status |= chip->codec_bit[chip->ac97_sdin[i]];
 		/* wait until all the probed codecs are ready */
 		end_time = jiffies + HZ;
 		do {
-			nstatus = igetdword(chip, ICHREG(GLOB_STA)) &
+			status = igetdword(chip, ICHREG(GLOB_STA)) &
 				chip->codec_isr_bits;
-			if (status == nstatus)
+			if (status == chip->codec_init_bits)
 				break;
 			schedule_timeout_uninterruptible(1);
 		} while (time_after_eq(end_time, jiffies));