i2c/eeprom: Only probe buses with DDC or SPD class

The eeprom driver shouldn't probe i2c buses which don't want to be
probed.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c
index 7dee001e5133..213a9f98decc 100644
--- a/drivers/i2c/chips/eeprom.c
+++ b/drivers/i2c/chips/eeprom.c
@@ -159,6 +159,8 @@ static struct bin_attribute eeprom_attr = {
 
 static int eeprom_attach_adapter(struct i2c_adapter *adapter)
 {
+        if (!(adapter->class & (I2C_CLASS_DDC | I2C_CLASS_SPD)))
+                return 0;
         return i2c_probe(adapter, &addr_data, eeprom_detect);
 }
 
@@ -169,6 +171,12 @@ static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
         struct eeprom_data *data;
         int err = 0;
 
+        /* EDID EEPROMs are often 24C00 EEPROMs, which answer to all
+           addresses 0x50-0x57, but we only care about 0x50. So decline
+           attaching to addresses >= 0x51 on DDC buses */
+        if (!(adapter->class & I2C_CLASS_SPD) && address >= 0x51)
+                goto exit;
+
         /* There are three ways we can read the EEPROM data:
            (1) I2C block reads (faster, but unsupported by most adapters)
            (2) Consecutive byte reads (100% overhead)