ALSA: hda_intel: add card number to irq description

Currently the info in /proc/interrupts doesn't allow to figure out which
interrupt belongs to which card (HDMI, PCH, ..).
Therefore add card details to the interrupt description.
With the patch the info in /proc/interrupts looks like this:

PCI-MSI 442368-edge      snd_hda_intel:card1
PCI-MSI 49152-edge      snd_hda_intel:card0

NOTE: this patch adds the new irq_descr field snd_card struct that is
filled automatically at a card object creation.  This can be used
generically for other drivers as well.  The changes for others will
follow later -- tiwai

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/core.h

@@ -99,6 +99,7 @@ struct snd_card {
 	char driver[16];		/* driver name */
 	char shortname[32];		/* short name of this soundcard */
 	char longname[80];		/* name of this soundcard */
+	char irq_descr[32];		/* Interrupt description */
 	char mixername[80];		/* mixer name */
 	char components[128];		/* card components delimited with
 								space */

sound/core/init.c

@@ -268,6 +268,9 @@ int snd_card_new(struct device *parent, int idx, const char *xid,
 	if (err < 0)
 		goto __error;
 
+	snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
+		 dev_driver_string(card->dev), dev_name(&card->card_dev));
+
 	/* the control interface cannot be accessed from the user space until */
 	/* snd_cards_bitmask and snd_cards are set with snd_card_register */
 	err = snd_ctl_create(card);

sound/pci/hda/hda_intel.c

@@ -725,7 +725,7 @@ static int azx_acquire_irq(struct azx *chip, int do_disconnect)
 
 	if (request_irq(chip->pci->irq, azx_interrupt,
 			chip->msi ? 0 : IRQF_SHARED,
-			KBUILD_MODNAME, chip)) {
+			chip->card->irq_descr, chip)) {
 		dev_err(chip->card->dev,
 			"unable to grab IRQ %d, disabling device\n",
 			chip->pci->irq);