Commit 8821c837 authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Wolfram Sang
Browse files

i2c: smbus: Prepare i2c_register_spd for usage on muxed segments 



If this is an adapter on a muxed bus segment, assume that each segment
is connected to a subset of the (> 8) overall memory slots. In this
case let's probe the maximum of 8 slots, however stop if the number
of overall populated slots is reached.

If we're not on a muxed segment and the total number of slots is > 8,
then warn because then not all SPD eeproms can be addressed.
Presumably the bus is muxed, but the mux config is missing.

Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
[wsa: removed a superfluous printout]
Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
parent eb520344

drivers/i2c/i2c-smbus.c

+12 −7
Original line number Diff line number Diff line
@@ -351,14 +351,19 @@ void i2c_register_spd(struct i2c_adapter *adap) 
	if (!dimm_count)

		return;



	dev_info(&adap->dev, "%d/%d memory slots populated (from DMI)\n",

		 dimm_count, slot_count);



	/*

	 * If we're a child adapter on a muxed segment, then limit slots to 8,

	 * as this is the max number of SPD EEPROMs that can be addressed per bus.

	 */

	if (i2c_parent_is_i2c_adapter(adap)) {

		slot_count = 8;

	} else {

		if (slot_count > 8) {

			dev_warn(&adap->dev,

			 "Systems with more than 8 memory slots not supported yet, not instantiating SPD\n");

				 "More than 8 memory slots on a single bus, contact i801 maintainer to add missing mux config\n");

			return;

		}

	}



	/*

	 * Memory types could be found at section 7.18.2 (Memory Device — Type), table 78