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i2c: smbus: Support up to 8 SPD EEPROMs

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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>
This commit is contained in:
Jean Delvare 2023-11-14 15:13:28 +01:00 committed by Wolfram Sang
parent 92a85b7c62
commit 13e3a512a2
1 changed files with 4 additions and 4 deletions
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8
drivers/i2c/i2c-smbus.c
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@ -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;
}