ALSA: hda - Fix buffer-alignment regression with Nvidia HDMI

The commit 2ae66c26
    ALSA: hda: option to enable arbitrary buffer/period sizes
introduced a regression on machines with Intel controller and Nvidia
HDMI.  The reason is that the driver modifies the global variable
align_buffer_size when an Intel controller is found, and the Nvidia
HDMI controller is probed after Intel although Nvidia chips require
the aligned buffers.

This patch fixes the problem by moving the flag into the local struct
so that it's not affected by other controllers.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42567

Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_intel.c

@@ -469,6 +469,7 @@ struct azx {
 	unsigned int irq_pending_warned :1;
 	unsigned int probing :1; /* codec probing phase */
 	unsigned int snoop:1;
+	unsigned int align_buffer_size:1;
 
 	/* for debugging */
 	unsigned int last_cmd[AZX_MAX_CODECS];
@@ -1690,7 +1691,7 @@ static int azx_pcm_open(struct snd_pcm_substream *substream)
 	runtime->hw.rates = hinfo->rates;
 	snd_pcm_limit_hw_rates(runtime);
 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
-	if (align_buffer_size)
+	if (chip->align_buffer_size)
 		/* constrain buffer sizes to be multiple of 128
 		   bytes. This is more efficient in terms of memory
 		   access but isn't required by the HDA spec and
@@ -2773,8 +2774,9 @@ static int __devinit azx_create(struct snd_card *card, struct pci_dev *pci,
 	}
 
 	/* disable buffer size rounding to 128-byte multiples if supported */
+	chip->align_buffer_size = align_buffer_size;
 	if (chip->driver_caps & AZX_DCAPS_BUFSIZE)
-		align_buffer_size = 0;
+		chip->align_buffer_size = 0;
 
 	/* allow 64bit DMA address if supported by H/W */
 	if ((gcap & ICH6_GCAP_64OK) && !pci_set_dma_mask(pci, DMA_BIT_MASK(64)))