[ALSA] cmipci: make the test for integrated MIDI port address more robust

Unused bytes in the I/O register range are likely to have the value 0x00
instead of 0xff, so test against both values when checking for the
presence of the integrated MIDI port.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 9 insertions, 6 deletions

diff --git a/sound/pci/cmipci.c b/sound/pci/cmipci.c
index 9d394c7c221d..6021e5c402ea 100644
--- a/sound/pci/cmipci.c
+++ b/sound/pci/cmipci.c
@@ -2827,7 +2827,7 @@ static int __devinit snd_cmipci_create(struct snd_card *card, struct pci_dev *pc
         };
         unsigned int val = 0;
         long iomidi;
-        int integrated_midi;
+        int integrated_midi = 0;
         int pcm_index, pcm_spdif_index;
         static struct pci_device_id intel_82437vx[] = {
                 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82437VX) },
@@ -2939,11 +2939,14 @@ static int __devinit snd_cmipci_create(struct snd_card *card, struct pci_dev *pc
                 return err;
         }
 
-        integrated_midi = cm->chip_version > 33 &&
-                snd_cmipci_read_b(cm, CM_REG_MPU_PCI + 1) != 0xff;
-        if (integrated_midi && mpu_port[dev] == 1)
-                iomidi = cm->iobase + CM_REG_MPU_PCI;
-        else {
+        if (cm->chip_version > 33 && mpu_port[dev] == 1) {
+                val = snd_cmipci_read_b(cm, CM_REG_MPU_PCI + 1);
+                if (val != 0x00 && val != 0xff) {
+                        iomidi = cm->iobase + CM_REG_MPU_PCI;
+                        integrated_midi = 1;
+                }
+        }
+        if (!integrated_midi) {
                 iomidi = mpu_port[dev];
                 switch (iomidi) {
                 case 0x320: val = CM_VMPU_320; break;