From 8821c8376993c271a77d241a4e657099f7400974 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sat, 2 Mar 2024 21:39:13 +0100 Subject: [PATCH] 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: Heiner Kallweit [wsa: removed a superfluous printout] Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-smbus.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c index 74807c6db596..97f338b123b1 100644 --- a/drivers/i2c/i2c-smbus.c +++ b/drivers/i2c/i2c-smbus.c @@ -351,13 +351,18 @@ 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 (slot_count > 8) { - dev_warn(&adap->dev, - "Systems with more than 8 memory slots not supported yet, not instantiating SPD\n"); - return; + /* + * 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, + "More than 8 memory slots on a single bus, contact i801 maintainer to add missing mux config\n"); + return; + } } /*