This is a note to let you know that I've just added the patch titled igc: Do not enable crosstimestamping for i225-V models to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: igc-do-not-enable-crosstimestamping-for-i225-v-model.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 20ec2803317bb1fe0fd98e87d3accdfb82d14a3e Author: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx> Date: Mon Dec 13 16:39:49 2021 -0800 igc: Do not enable crosstimestamping for i225-V models [ Upstream commit 1e81dcc1ab7de7a789e60042ce82d5a612632599 ] It was reported that when PCIe PTM is enabled, some lockups could be observed with some integrated i225-V models. While the issue is investigated, we can disable crosstimestamp for those models and see no loss of functionality, because those models don't have any support for time synchronization. Fixes: a90ec8483732 ("igc: Add support for PTP getcrosststamp()") Link: https://lore.kernel.org/all/924175a188159f4e03bd69908a91e606b574139b.camel@xxxxxx/ Reported-by: Stefan Dietrich <roots@xxxxxx> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx> Tested-by: Nechama Kraus <nechamax.kraus@xxxxxxxxxxxxxxx> Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c index 30568e3544cda..4f9245aa79a18 100644 --- a/drivers/net/ethernet/intel/igc/igc_ptp.c +++ b/drivers/net/ethernet/intel/igc/igc_ptp.c @@ -768,7 +768,20 @@ int igc_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr) */ static bool igc_is_crosststamp_supported(struct igc_adapter *adapter) { - return IS_ENABLED(CONFIG_X86_TSC) ? pcie_ptm_enabled(adapter->pdev) : false; + if (!IS_ENABLED(CONFIG_X86_TSC)) + return false; + + /* FIXME: it was noticed that enabling support for PCIe PTM in + * some i225-V models could cause lockups when bringing the + * interface up/down. There should be no downsides to + * disabling crosstimestamping support for i225-V, as it + * doesn't have any PTP support. That way we gain some time + * while root causing the issue. + */ + if (adapter->pdev->device == IGC_DEV_ID_I225_V) + return false; + + return pcie_ptm_enabled(adapter->pdev); } static struct system_counterval_t igc_device_tstamp_to_system(u64 tstamp)