[alsa-devel] als4000: enable burst mode

[Ondrej Zary]

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>

--- 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	2010-08-03 23:50:08.000000000 +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) | 0x04);
 	spin_unlock_irq(&chip->reg_lock);
 }
 


-- 
Ondrej Zary