Re: [1/2] 2.6.21-rc7: known regressions

[Michal Piotrowski <michal.k.k.piotrowski@gmail.com>]

Hi Takashi,

Takashi Iwai napisał(a):
> At Mon, 16 Apr 2007 17:44:57 -0400,
> Chuck Ebbert wrote:
>> Adrian Bunk wrote:
>>
>>> This email lists some known regressions in Linus' tree compared to 2.6.20.
>>>
>>> Subject    : snd_intel8x0: divide error: 0000
>>> References : http://lkml.org/lkml/2007/3/5/252
>>> Submitter  : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
>>> Status     : unknown
>>>
>> Oops is in sound/pci/intel8x0.c::snd_intel8x0_update(), part of
>> the interrupt handler:
>>
>> Line 751:
>>
>>         ichdev->position += step * ichdev->fragsize1;
>>         if (! chip->in_measurement)
>>                 ichdev->position %= ichdev->size;
>>
>> ichdev->size is 0. Interrupt happened upon request_irq().
>>
>> Does chip->in_measurement need to be reset because this is a
>> crashdump kernel?
> 
> No, the problem seems to be the timing of request_irq() and the
> initialization of hardware.  The irq handler shouldn't get called
> there at all.
> 
> How about the patch below?
> 
> 
> Takashi
> 
> diff -r 4b6ed4ef4820 sound/pci/intel8x0.c
> --- a/sound/pci/intel8x0.c	Mon Apr 16 19:20:17 2007 +0200
> +++ b/sound/pci/intel8x0.c	Tue Apr 17 11:02:49 2007 +0200
> @@ -2493,6 +2493,7 @@ static int intel8x0_resume(struct pci_de
>  		return -EIO;
>  	}
>  	pci_set_master(pci);
> +	snd_intel8x0_chip_init(chip, 0);
>  	if (request_irq(pci->irq, snd_intel8x0_interrupt,
>  			IRQF_SHARED, card->shortname, chip)) {
>  		printk(KERN_ERR "intel8x0: unable to grab IRQ %d, "
> @@ -2502,7 +2503,6 @@ static int intel8x0_resume(struct pci_de
>  	}
>  	chip->irq = pci->irq;
>  	synchronize_irq(chip->irq);
> -	snd_intel8x0_chip_init(chip, 0);
>  
>  	/* re-initialize mixer stuff */
>  	if (chip->device_type == DEVICE_INTEL_ICH4 && !spdif_aclink) {
> @@ -2862,16 +2862,7 @@ static int __devinit snd_intel8x0_create
>  		ICH_REG_ALI_INTERRUPTSR : ICH_REG_GLOB_STA;
>  	chip->int_sta_mask = int_sta_masks;
>  
> -	/* request irq after initializaing int_sta_mask, etc */
> -	if (request_irq(pci->irq, snd_intel8x0_interrupt,
> -			IRQF_SHARED, card->shortname, chip)) {
> -		snd_printk(KERN_ERR "unable to grab IRQ %d\n", pci->irq);
> -		snd_intel8x0_free(chip);
> -		return -EBUSY;
> -	}
> -	chip->irq = pci->irq;
>  	pci_set_master(pci);
> -	synchronize_irq(chip->irq);
>  
>  	switch(chip->device_type) {
>  	case DEVICE_INTEL_ICH4:
> @@ -2900,6 +2891,15 @@ static int __devinit snd_intel8x0_create
>  		snd_intel8x0_free(chip);
>  		return err;
>  	}
> +
> +	/* request irq after initializaing int_sta_mask, etc */
> +	if (request_irq(pci->irq, snd_intel8x0_interrupt,
> +			IRQF_SHARED, card->shortname, chip)) {
> +		snd_printk(KERN_ERR "unable to grab IRQ %d\n", pci->irq);
> +		snd_intel8x0_free(chip);
> +		return -EBUSY;
> +	}
> +	chip->irq = pci->irq;
>  
>  	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
>  		snd_intel8x0_free(chip);
> 

This patch solves the problem for me. Thanks!

Regards,
Michal

-- 
Michal K. K. Piotrowski
LTG - Linux Testers Group (PL)
(http://www.stardust.webpages.pl/ltg/)
LTG - Linux Testers Group (EN)
(http://www.stardust.webpages.pl/linux_testers_group_en/)