[alsa-devel] als4000: enable burst mode

[Takashi Iwai]

At Wed, 4 Aug 2010 21:08:14 +0200,
Ondrej Zary wrote:
> 
> On Wednesday 04 August 2010 07:43:44 Takashi Iwai wrote:
> > At Tue, 3 Aug 2010 23:57:05 +0200,
> >
> > Ondrej Zary wrote:
> > > Enable burst mode to prevent dropouts during high PCI bus usage.
> > > The card is useless in X without this because of dropouts when anything
> > > moves on the screen (at least with PCI VGA card). Enabling this is also
> > > recommended by the datasheet (page 48).
> > >
> > > Signed-off-by: Ondrej Zary <linux at rainbow-software.org>
> >
> > Applied now.  Thanks.
> 
> My previous patch assumed that the DMA mode (represented by 3 lowest bits of
> ALS4K_GCR99_DMA_EMULATION_CTRL register) is set to the default value 0. If
> that's not the case, it might result in invalid mode to be set. This v2 patch
> fixes this potential problem.
> 
> Signed-off-by: Ondrej Zary <linux at rainbow-software.org>

As the previous patch was already applied, could you give the
incremental change?


thanks,

Takashi

> --- linux-2.6.35-rc2/sound/pci/als4000.c	2010-06-06 05:43:24.000000000 +0200
> +++ linux-2.6.35-rc3/sound/pci/als4000.c	2010-08-04 20:57:00.000000000 +0200
> @@ -763,9 +763,9 @@ static void snd_als4000_configure(struct
>  	/* SPECS_PAGE: 39 */
>  	for (i = ALS4K_GCR91_DMA0_ADDR; i <= ALS4K_GCR96_DMA3_MODE_COUNT; ++i)
>  		snd_als4k_gcr_write(chip, i, 0);
> -	
> +	/* enable burst mode to prevent dropouts during high PCI bus usage */
>  	snd_als4k_gcr_write(chip, ALS4K_GCR99_DMA_EMULATION_CTRL,
> -		snd_als4k_gcr_read(chip, ALS4K_GCR99_DMA_EMULATION_CTRL));
> +		(snd_als4k_gcr_read(chip, ALS4K_GCR99_DMA_EMULATION_CTRL) & ~0x07) | 0x04);
>  	spin_unlock_irq(&chip->reg_lock);
>  }
>  
> 
> 
> -- 
> Ondrej Zary
>