i2c: smbus: Support up to 8 SPD EEPROMs

I originally restricted i2c_register_spd() to only support systems
with up to 4 memory slots, so that we can experiment with it on
a limited numbers of systems. It's been more than 3 years and it
seems to work just fine, so the time has come to lift this arbitrary
limitation.

The maximum number of memory slots which can be connected to a single
I2C segment is 8, so support that many SPD EEPROMs. Any system with
more than 8 memory slots would have either multiple SMBus channels
or SMBus multiplexing, so it would need dedicated care. We'll get to
that later as needed.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index 138c3f5e0093a5c2f8ceeb6ddeca991dd70fbad6..74807c6db596d810fffe035268875a61b1074881 100644 (file)
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -308,8 +308,8 @@ EXPORT_SYMBOL_GPL(i2c_free_slave_host_notify_device);
  * target systems are the same.
  * Restrictions to automatic SPD instantiation:
  *  - Only works if all filled slots have the same memory type
- *  - Only works for DDR2, DDR3 and DDR4 for now
- *  - Only works on systems with 1 to 4 memory slots
+ *  - Only works for DDR, DDR2, DDR3 and DDR4 for now
+ *  - Only works on systems with 1 to 8 memory slots
  */
 #if IS_ENABLED(CONFIG_DMI)
 void i2c_register_spd(struct i2c_adapter *adap)
@@ -354,9 +354,9 @@ void i2c_register_spd(struct i2c_adapter *adap)
        dev_info(&adap->dev, "%d/%d memory slots populated (from DMI)\n",
                 dimm_count, slot_count);
 
-       if (slot_count > 4) {
+       if (slot_count > 8) {
                dev_warn(&adap->dev,
-                        "Systems with more than 4 memory slots not supported yet, not instantiating SPD\n");
+                        "Systems with more than 8 memory slots not supported yet, not instantiating SPD\n");
                return;
        }