From: Sumit Gupta Date: Wed, 27 May 2026 14:01:25 +0000 (+0530) Subject: memory: tegra186-emc: stop borrowing MC aggregate hook for EMC X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2e05f3d6005d9aa3e2e423d2471f290d9ccbe3d2;p=thirdparty%2Flinux.git memory: tegra186-emc: stop borrowing MC aggregate hook for EMC tegra186_emc_interconnect_init() copies the MC's ICC aggregate hook into the EMC provider. That hook (tegra234_mc_icc_aggregate / tegra264_mc_icc_aggregate) uses container_of() to recover 'mc', which is only valid when the icc_provider is embedded in struct tegra_mc. For an EMC node the provider is embedded in struct tegra186_emc, so 'mc' points into unrelated memory. This stayed harmless until commit faafd6ca7e6e ("memory: tegra: make icc_set_bw return zero if BWMGR not supported") added an unconditional read of mc->bwmgr_mrq_supported at the top of the hook. UBSAN catches the stray load on every EMC aggregation: UBSAN: invalid-load in drivers/memory/tegra/tegra234.c:1104:9 load of value 112 is not a valid value for type '_Bool' No functional impact in practice, since the hook's only other mc dereference (mc->num_channels) sits inside a TEGRA_ICC_MC_CPU_CLUSTER* branch that EMC nodes never enter. Fix this by setting the EMC provider's aggregate hook to icc_std_aggregate, instead of borrowing the MC's hook. The MC providers continue using their own aggregate hooks, where container_of() correctly resolves to struct tegra_mc. Reported-by: Jon Hunter Fixes: 9a38cb27668e ("memory: tegra: Add interconnect support for DRAM scaling in Tegra234") Signed-off-by: Sumit Gupta Reviewed-by: Jon Hunter Tested-by: Jon Hunter Link: https://patch.msgid.link/20260527140127.49172-2-sumitg@nvidia.com Signed-off-by: Krzysztof Kozlowski --- diff --git a/drivers/memory/tegra/tegra186-emc.c b/drivers/memory/tegra/tegra186-emc.c index 03ebab6fbe68..f71265b303b9 100644 --- a/drivers/memory/tegra/tegra186-emc.c +++ b/drivers/memory/tegra/tegra186-emc.c @@ -258,15 +258,13 @@ static int tegra186_emc_icc_get_init_bw(struct icc_node *node, u32 *avg, u32 *pe static int tegra186_emc_interconnect_init(struct tegra186_emc *emc) { - struct tegra_mc *mc = dev_get_drvdata(emc->dev->parent); - const struct tegra_mc_soc *soc = mc->soc; struct icc_node *node; int err; emc->provider.dev = emc->dev; emc->provider.set = tegra186_emc_icc_set_bw; emc->provider.data = &emc->provider; - emc->provider.aggregate = soc->icc_ops->aggregate; + emc->provider.aggregate = icc_std_aggregate; emc->provider.xlate = tegra186_emc_of_icc_xlate; emc->provider.get_bw = tegra186_emc_icc_get_init_bw;