Commit 0f886f19 authored Aug 21, 2023 by Alessio Igor Bogani Committed by Greg Kroah-Hartman Aug 30, 2023

igb: Avoid starting unnecessary workqueues



[ Upstream commit b888c510f7b3d64ca75fc0f43b4a4bd1a611312f ]

If ptp_clock_register() fails or CONFIG_PTP isn't enabled, avoid starting
PTP related workqueues.

In this way we can fix this:
 BUG: unable to handle page fault for address: ffffc9000440b6f8
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 100000067 P4D 100000067 PUD 1001e0067 PMD 107dc5067 PTE 0
 Oops: 0000 [#1] PREEMPT SMP
 [...]
 Workqueue: events igb_ptp_overflow_check
 RIP: 0010:igb_rd32+0x1f/0x60
 [...]
 Call Trace:
  igb_ptp_read_82580+0x20/0x50
  timecounter_read+0x15/0x60
  igb_ptp_overflow_check+0x1a/0x50
  process_one_work+0x1cb/0x3c0
  worker_thread+0x53/0x3f0
  ? rescuer_thread+0x370/0x370
  kthread+0x142/0x160
  ? kthread_associate_blkcg+0xc0/0xc0
  ret_from_fork+0x1f/0x30

Fixes: 1f6e8178 ("igb: Prevent dropped Tx timestamps via work items and interrupts.")
Fixes: d339b133 ("igb: add PTP Hardware Clock code")
Signed-off-by: Alessio Igor Bogani <alessio.bogani@elettra.eu>
Tested-by: Arpana Arland <arpanax.arland@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230821171927.2203644-1-anthony.l.nguyen@intel.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 09c35cd6

drivers/net/ethernet/intel/igb/igb_ptp.c

+12 −12

Original line number	Diff line number	Diff line
		@@ -1181,6 +1181,16 @@ void igb_ptp_init(struct igb_adapter *adapter)
		return;
		}

		adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps,
		&adapter->pdev->dev);
		if (IS_ERR(adapter->ptp_clock)) {
		adapter->ptp_clock = NULL;
		dev_err(&adapter->pdev->dev, "ptp_clock_register failed\n");
		} else if (adapter->ptp_clock) {
		dev_info(&adapter->pdev->dev, "added PHC on %s\n",
		adapter->netdev->name);
		adapter->ptp_flags \|= IGB_PTP_ENABLED;

		spin_lock_init(&adapter->tmreg_lock);
		INIT_WORK(&adapter->ptp_tx_work, igb_ptp_tx_work);

		@@ -1192,16 +1202,6 @@ void igb_ptp_init(struct igb_adapter *adapter)
		adapter->tstamp_config.tx_type = HWTSTAMP_TX_OFF;

		igb_ptp_reset(adapter);

		adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps,
		&adapter->pdev->dev);
		if (IS_ERR(adapter->ptp_clock)) {
		adapter->ptp_clock = NULL;
		dev_err(&adapter->pdev->dev, "ptp_clock_register failed\n");
		} else if (adapter->ptp_clock) {
		dev_info(&adapter->pdev->dev, "added PHC on %s\n",
		adapter->netdev->name);
		adapter->ptp_flags \|= IGB_PTP_ENABLED;
		}
		}