[ALSA] cs4236-irq-handling-fix.patch

CS4236+ driver
Background: The card/chipset supports an external MIDI interrupt. By
default, this interrupt isn't used (because the isapnp mechanism chooses a
configuration without an assigned interrupt). If the user wishes to
explicitly select an interrupt via the mpu_irq parameter for such a
configured device, it doesn't work: The driver always shows:

isapnp MPU: port=0x330, irq=-1

(note the 'irq=-1')

Problem: The driver only allows to set the irq if pnp_irq_valid returns
true for this particular pnp device. This, however, is only true if an
interrupt has already been assigned (pnp_valid_irq returns true if the flag
IORESOURCE_IRQ is set and IORESOURCE_UNSET is not set). If no interrupt
has been assigned so far, IORESOURCE_UNSET is set and pnp_irq_valid returns
false, thereby inhibiting the selection of a valid irq.

Solution: Don't check for a valid (= already assigned) irq at the point of
calling pnp_resource_change.

Tested successfully on Linux 2.6.11.

Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Jaroslav Kysela <[e-mail]>

sound/isa/cs423x/cs4236.c

···
 		pnp_init_resource_table(cfg);
 		if (mpu_port[dev] != SNDRV_AUTO_PORT)
 			pnp_resource_change(&cfg->port_resource[0], mpu_port[dev], 2);
-		if (mpu_irq[dev] != SNDRV_AUTO_IRQ && mpu_irq[dev] >= 0 &&
-		    pnp_irq_valid(pdev, 0))
+		if (mpu_irq[dev] != SNDRV_AUTO_IRQ && mpu_irq[dev] >= 0)
 			pnp_resource_change(&cfg->irq_resource[0], mpu_irq[dev], 1);
 		err = pnp_manual_config_dev(pdev, cfg, 0);
 		if (err < 0)