3 files changed, 48 insertions, 0 deletions
diff --git a/sound/pci/oxygen/oxygen.h b/sound/pci/oxygen/oxygen.h
index c500d48ea34..bd615dbffad 100644
--- a/sound/pci/oxygen/oxygen.h
+++ b/sound/pci/oxygen/oxygen.h
@@ -18,6 +18,8 @@
 
 #define OXYGEN_IO_SIZE	0x100
 
+#define OXYGEN_EEPROM_ID	0x434d	/* "CM" */
+
 /* model-specific configuration of outputs/inputs */
 #define PLAYBACK_0_TO_I2S	0x0001
      /* PLAYBACK_0_TO_AC97_0		not implemented */
@@ -190,6 +192,7 @@ void oxygen_reset_uart(struct oxygen *chip);
 void oxygen_write_uart(struct oxygen *chip, u8 data);
 
 u16 oxygen_read_eeprom(struct oxygen *chip, unsigned int index);
+void oxygen_write_eeprom(struct oxygen *chip, unsigned int index, u16 value);
 
 static inline void oxygen_set_bits8(struct oxygen *chip,
 				    unsigned int reg, u8 value)
diff --git a/sound/pci/oxygen/oxygen_io.c b/sound/pci/oxygen/oxygen_io.c
index 05f48ef1a44..c1eb923f2ac 100644
--- a/sound/pci/oxygen/oxygen_io.c
+++ b/sound/pci/oxygen/oxygen_io.c
@@ -269,3 +269,19 @@ u16 oxygen_read_eeprom(struct oxygen *chip, unsigned int index)
 	}
 	return oxygen_read16(chip, OXYGEN_EEPROM_DATA);
 }
+
+void oxygen_write_eeprom(struct oxygen *chip, unsigned int index, u16 value)
+{
+	unsigned int timeout;
+
+	oxygen_write16(chip, OXYGEN_EEPROM_DATA, value);
+	oxygen_write8(chip, OXYGEN_EEPROM_CONTROL,
+		      index | OXYGEN_EEPROM_DIR_WRITE);
+	for (timeout = 0; timeout < 10; ++timeout) {
+		msleep(1);
+		if (!(oxygen_read8(chip, OXYGEN_EEPROM_STATUS)
+		      & OXYGEN_EEPROM_BUSY))
+			return;
+	}
+	snd_printk(KERN_ERR "EEPROM write timeout\n");
+}
diff --git a/sound/pci/oxygen/oxygen_lib.c b/sound/pci/oxygen/oxygen_lib.c
index d83c3a95732..6e1cdd2fd76 100644
--- a/sound/pci/oxygen/oxygen_lib.c
+++ b/sound/pci/oxygen/oxygen_lib.c
@@ -272,6 +272,34 @@ oxygen_search_pci_id(struct oxygen *chip, const struct pci_device_id ids[])
 	return NULL;
 }
 
+static void oxygen_restore_eeprom(struct oxygen *chip,
+				  const struct pci_device_id *id)
+{
+	if (oxygen_read_eeprom(chip, 0) != OXYGEN_EEPROM_ID) {
+		/*
+		 * This function gets called only when a known card model has
+		 * been detected, i.e., we know there is a valid subsystem
+		 * product ID at index 2 in the EEPROM.  Therefore, we have
+		 * been able to deduce the correct subsystem vendor ID, and
+		 * this is enough information to restore the original EEPROM
+		 * contents.
+		 */
+		oxygen_write_eeprom(chip, 1, id->subvendor);
+		oxygen_write_eeprom(chip, 0, OXYGEN_EEPROM_ID);
+
+		oxygen_set_bits8(chip, OXYGEN_MISC,
+				 OXYGEN_MISC_WRITE_PCI_SUBID);
+		pci_write_config_word(chip->pci, PCI_SUBSYSTEM_VENDOR_ID,
+				      id->subvendor);
+		pci_write_config_word(chip->pci, PCI_SUBSYSTEM_ID,
+				      id->subdevice);
+		oxygen_clear_bits8(chip, OXYGEN_MISC,
+				   OXYGEN_MISC_WRITE_PCI_SUBID);
+
+		snd_printk(KERN_INFO "EEPROM ID restored\n");
+	}
+}
+
 static void oxygen_init(struct oxygen *chip)
 {
 	unsigned int i;
@@ -532,6 +560,7 @@ int oxygen_pci_probe(struct pci_dev *pci, int index, char *id,
 		err = -ENODEV;
 		goto err_pci_regions;
 	}
+	oxygen_restore_eeprom(chip, pci_id);
 	err = get_model(chip, pci_id);
 	if (err < 0)
 		goto err_pci_regions;