From 894f475f88e06c0f352c829849560790dbdedbe5 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Wed, 19 Nov 2025 09:50:01 +0100 Subject: [PATCH 1/5] PCI/PM: Reinstate clearing state_saved in legacy and !PM codepaths When a PCI device is suspended, it is normally the PCI core's job to save Config Space and put the device into a low power state. However drivers are allowed to assume these responsibilities. When they do, the PCI core can tell by looking at the state_saved flag in struct pci_dev: The flag is cleared before commencing the suspend sequence and it is set when pci_save_state() is called. If the PCI core finds the flag set late in the suspend sequence, it refrains from calling pci_save_state() itself. But there are two corner cases where the PCI core neglects to clear the flag before commencing the suspend sequence: * If a driver has legacy PCI PM callbacks, pci_legacy_suspend() neglects to clear the flag. The (stale) flag is subsequently queried by pci_legacy_suspend() itself and pci_legacy_suspend_late(). * If a device has no driver or its driver has no PCI PM callbacks, pci_pm_freeze() neglects to clear the flag. The (stale) flag is subsequently queried by pci_pm_freeze_noirq(). The flag may be set prior to suspend if the device went through error recovery: Drivers commonly invoke pci_restore_state() + pci_save_state() to restore Config Space after reset. The flag may also be set if drivers call pci_save_state() on probe to allow for recovery from subsequent errors. The result is that pci_legacy_suspend_late() and pci_pm_freeze_noirq() don't call pci_save_state() and so the state that will be restored on resume is the one recorded on last error recovery or on probe, not the one that the device had on suspend. If the two states happen to be identical, there's no problem. Reinstate clearing the flag in pci_legacy_suspend() and pci_pm_freeze(). The two functions used to do that until commit 4b77b0a2ba27 ("PCI: Clear saved_state after the state has been restored") deemed it unnecessary because it assumed that it's sufficient to clear the flag on resume in pci_restore_state(). The commit seemingly did not take into account that pci_save_state() and pci_restore_state() are not only used by power management code, but also for error recovery. Devices without driver or whose driver has no PCI PM callbacks may be in runtime suspend when pci_pm_freeze() is called. Their state has already been saved, so don't clear the flag to skip a pointless pci_save_state() in pci_pm_freeze_noirq(). None of the drivers with legacy PCI PM callbacks seem to use runtime PM, so clear the flag unconditionally in their case. Fixes: 4b77b0a2ba27 ("PCI: Clear saved_state after the state has been restored") Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki (Intel) Cc: stable@vger.kernel.org # v2.6.32+ Link: https://patch.msgid.link/094f2aad64418710daf0940112abe5a0afdc6bce.1763483367.git.lukas@wunner.de --- drivers/pci/pci-driver.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 302d61783f6c..327b21c48614 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -629,6 +629,8 @@ static int pci_legacy_suspend(struct device *dev, pm_message_t state) struct pci_dev *pci_dev = to_pci_dev(dev); struct pci_driver *drv = pci_dev->driver; + pci_dev->state_saved = false; + if (drv && drv->suspend) { pci_power_t prev = pci_dev->current_state; int error; @@ -1036,6 +1038,8 @@ static int pci_pm_freeze(struct device *dev) if (!pm) { pci_pm_default_suspend(pci_dev); + if (!pm_runtime_suspended(dev)) + pci_dev->state_saved = false; return 0; } From be9edde43d85d301a9b9d9678f34b3c111b85ead Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Wed, 19 Nov 2025 09:50:02 +0100 Subject: [PATCH 2/5] PCI/PM: Stop needlessly clearing state_saved on enumeration and thaw The state_saved flag tells the PCI core whether a driver assumes responsibility to save Config Space and put the device into a low power state on suspend. The flag is currently initialized to false on enumeration, even though it already is false (because struct pci_dev is zeroed by kzalloc()) and even though it is set to false before commencing the suspend sequence (the only code path where it's relevant). The flag is also set to false in pci_pm_thaw(), i.e. on resume, when it's no longer relevant. Drop these two superfluous flag assignments for simplicity. Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki (Intel) Link: https://patch.msgid.link/fd167945bd7852e1ca08cd4b202130659eea2c2f.1763483367.git.lukas@wunner.de --- drivers/pci/pci-driver.c | 2 -- drivers/pci/probe.c | 2 -- 2 files changed, 4 deletions(-) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 327b21c48614..7c2d9d596258 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1133,8 +1133,6 @@ static int pci_pm_thaw(struct device *dev) pci_pm_reenable_device(pci_dev); } - pci_dev->state_saved = false; - return error; } diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c83e75a0ec12..c7c7a3d5ec0f 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2747,8 +2747,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) pci_reassigndev_resource_alignment(dev); - dev->state_saved = false; - pci_init_capabilities(dev); /* From a2f1e22390ac2ca7ac8d77aa0f78c068b6dd2208 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Wed, 19 Nov 2025 09:50:03 +0100 Subject: [PATCH 3/5] PCI/ERR: Ensure error recoverability at all times When the PCI core gained power management support in 2002, it introduced pci_save_state() and pci_restore_state() helpers to restore Config Space after a D3hot or D3cold transition, which implies a Soft or Fundamental Reset (PCIe r7.0 sec 5.8): https://git.kernel.org/tglx/history/c/a5287abe398b In 2006, EEH and AER were introduced to recover from errors by performing a reset. Because errors can occur at any time, drivers began calling pci_save_state() on probe to ensure recoverability. In 2009, recoverability was foiled by commit c82f63e411f1 ("PCI: check saved state before restore"): It amended pci_restore_state() to bail out if the "state_saved" flag has been cleared. The flag is cleared by pci_restore_state() itself, hence a saved state is now allowed to be restored only once and is then invalidated. That doesn't seem to make sense because the saved state should be good enough to be reused. Soon after, drivers began to work around this behavior by calling pci_save_state() immediately after pci_restore_state(), see e.g. commit b94f2d775a71 ("igb: call pci_save_state after pci_restore_state"). Hilariously, two drivers even set the "saved_state" flag to true before invoking pci_restore_state(), see ipr_reset_restore_cfg_space() and e1000_io_slot_reset(). Despite these workarounds, recoverability at all times is not guaranteed: E.g. when a PCIe port goes through a runtime suspend and resume cycle, the "saved_state" flag is cleared by: pci_pm_runtime_resume() pci_pm_default_resume_early() pci_restore_state() ... and hence on a subsequent AER event, the port's Config Space cannot be restored. Riana reports a recovery failure of a GPU-integrated PCIe switch and has root-caused it to the behavior of pci_restore_state(). Another workaround would be necessary, namely calling pci_save_state() in pcie_port_device_runtime_resume(). The motivation of commit c82f63e411f1 was to prevent restoring state if pci_save_state() hasn't been called before. But that can be achieved by saving state already on device addition, after Config Space has been initialized. A desirable side effect is that devices become recoverable even if no driver gets bound. This renders the commit unnecessary, so revert it. Reported-by: Riana Tauro # off-list Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Tested-by: Riana Tauro Reviewed-by: Rafael J. Wysocki (Intel) Link: https://patch.msgid.link/9e34ce61c5404e99ffdd29205122c6fb334b38aa.1763483367.git.lukas@wunner.de --- drivers/pci/bus.c | 3 +++ drivers/pci/pci.c | 3 --- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index f26aec6ff588..9daf13ed3714 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -357,6 +357,9 @@ void pci_bus_add_device(struct pci_dev *dev) pci_proc_attach_device(dev); pci_bridge_d3_update(dev); + /* Save config space for error recoverability */ + pci_save_state(dev); + /* * If the PCI device is associated with a pwrctrl device with a * power supply, create a device link between the PCI device and diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b14dd064006c..2f0da5dbbba4 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1855,9 +1855,6 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) */ void pci_restore_state(struct pci_dev *dev) { - if (!dev->state_saved) - return; - pci_restore_pcie_state(dev); pci_restore_pasid_state(dev); pci_restore_pri_state(dev); From 383d89699c5028de510a6667f674ed38585f77fc Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Sun, 12 Oct 2025 15:25:02 +0200 Subject: [PATCH 4/5] treewide: Drop pci_save_state() after pci_restore_state() In 2009, commit c82f63e411f1 ("PCI: check saved state before restore") changed the behavior of pci_restore_state() such that it became necessary to call pci_save_state() afterwards, lest recovery from subsequent PCI errors fails. The commit has just been reverted and so all the pci_save_state() after pci_restore_state() calls that have accumulated in the tree are now superfluous. Drop them. Two drivers chose a different approach to achieve the same result: drivers/scsi/ipr.c and drivers/net/ethernet/intel/e1000e/netdev.c set the pci_dev's "state_saved" flag to true before calling pci_restore_state(). Drop this as well. Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Acked-by: Dave Jiang Acked-by: Giovanni Cabiddu # qat Link: https://patch.msgid.link/c2b28cc4defa1b743cf1dedee23c455be98b397a.1760274044.git.lukas@wunner.de --- drivers/crypto/intel/qat/qat_common/adf_aer.c | 2 -- drivers/dma/ioat/init.c | 1 - drivers/net/ethernet/broadcom/bnx2.c | 2 -- drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 1 - drivers/net/ethernet/broadcom/tg3.c | 1 - drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c | 1 - drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 2 -- drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c | 1 - drivers/net/ethernet/intel/e1000e/netdev.c | 1 - drivers/net/ethernet/intel/fm10k/fm10k_pci.c | 6 ------ drivers/net/ethernet/intel/i40e/i40e_main.c | 1 - drivers/net/ethernet/intel/ice/ice_main.c | 2 -- drivers/net/ethernet/intel/igb/igb_main.c | 2 -- drivers/net/ethernet/intel/igc/igc_main.c | 2 -- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 1 - drivers/net/ethernet/mellanox/mlx4/main.c | 1 - drivers/net/ethernet/mellanox/mlx5/core/main.c | 1 - drivers/net/ethernet/meta/fbnic/fbnic_pci.c | 1 - drivers/net/ethernet/microchip/lan743x_main.c | 1 - drivers/net/ethernet/myricom/myri10ge/myri10ge.c | 4 ---- drivers/net/ethernet/neterion/s2io.c | 1 - drivers/pci/pcie/portdrv.c | 1 - drivers/scsi/bfa/bfad.c | 1 - drivers/scsi/csiostor/csio_init.c | 1 - drivers/scsi/ipr.c | 1 - drivers/scsi/lpfc/lpfc_init.c | 6 ------ drivers/scsi/qla2xxx/qla_os.c | 5 ----- drivers/scsi/qla4xxx/ql4_os.c | 5 ----- drivers/tty/serial/8250/8250_pci.c | 1 - drivers/tty/serial/jsm/jsm_driver.c | 1 - 30 files changed, 57 deletions(-) diff --git a/drivers/crypto/intel/qat/qat_common/adf_aer.c b/drivers/crypto/intel/qat/qat_common/adf_aer.c index 35679b21ff63..9a5a4b35ce71 100644 --- a/drivers/crypto/intel/qat/qat_common/adf_aer.c +++ b/drivers/crypto/intel/qat/qat_common/adf_aer.c @@ -105,7 +105,6 @@ void adf_dev_restore(struct adf_accel_dev *accel_dev) accel_dev->accel_id); hw_device->reset_device(accel_dev); pci_restore_state(pdev); - pci_save_state(pdev); } } @@ -204,7 +203,6 @@ static pci_ers_result_t adf_slot_reset(struct pci_dev *pdev) if (!pdev->is_busmaster) pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); res = adf_dev_up(accel_dev, false); if (res && res != -EALREADY) return PCI_ERS_RESULT_DISCONNECT; diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c index 02f68b328511..227398673b73 100644 --- a/drivers/dma/ioat/init.c +++ b/drivers/dma/ioat/init.c @@ -1286,7 +1286,6 @@ static pci_ers_result_t ioat_pcie_error_slot_reset(struct pci_dev *pdev) } else { pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); pci_wake_from_d3(pdev, false); } diff --git a/drivers/net/ethernet/broadcom/bnx2.c b/drivers/net/ethernet/broadcom/bnx2.c index cb1011f6fd30..805daae9dd36 100644 --- a/drivers/net/ethernet/broadcom/bnx2.c +++ b/drivers/net/ethernet/broadcom/bnx2.c @@ -6444,7 +6444,6 @@ bnx2_reset_task(struct work_struct *work) if (!(pcicmd & PCI_COMMAND_MEMORY)) { /* in case PCI block has reset */ pci_restore_state(bp->pdev); - pci_save_state(bp->pdev); } rc = bnx2_init_nic(bp, 1); if (rc) { @@ -8718,7 +8717,6 @@ static pci_ers_result_t bnx2_io_slot_reset(struct pci_dev *pdev) } else { pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); if (netif_running(dev)) err = bnx2_init_nic(bp, 1); diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c index f0f05d7315ac..8e6eec828d48 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c @@ -14216,7 +14216,6 @@ static pci_ers_result_t bnx2x_io_slot_reset(struct pci_dev *pdev) pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); if (netif_running(dev)) bnx2x_set_power_state(bp, PCI_D0); diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index 7f00ec7fd7b9..ecc12206a8e9 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -18352,7 +18352,6 @@ static pci_ers_result_t tg3_io_slot_reset(struct pci_dev *pdev) pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); if (!netdev || !netif_running(netdev)) { rc = PCI_ERS_RESULT_RECOVERED; diff --git a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c index f92a3550e480..3b1321c8ed14 100644 --- a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c +++ b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c @@ -2933,7 +2933,6 @@ static int t3_reenable_adapter(struct adapter *adapter) } pci_set_master(adapter->pdev); pci_restore_state(adapter->pdev); - pci_save_state(adapter->pdev); /* Free sge resources */ t3_free_sge_resources(adapter); diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c index 392723ef14e5..1ce2091cdc01 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c @@ -5456,7 +5456,6 @@ static pci_ers_result_t eeh_slot_reset(struct pci_dev *pdev) if (!adap) { pci_restore_state(pdev); - pci_save_state(pdev); return PCI_ERS_RESULT_RECOVERED; } @@ -5471,7 +5470,6 @@ static pci_ers_result_t eeh_slot_reset(struct pci_dev *pdev) pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); if (t4_wait_dev_ready(adap->regs) < 0) return PCI_ERS_RESULT_DISCONNECT; diff --git a/drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c b/drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c index 83cf75bf7a17..2eb1e3d699d6 100644 --- a/drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c +++ b/drivers/net/ethernet/hisilicon/hibmcge/hbg_err.c @@ -158,7 +158,6 @@ static pci_ers_result_t hbg_pci_err_slot_reset(struct pci_dev *pdev) pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); hbg_err_reset(priv); return PCI_ERS_RESULT_RECOVERED; diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 201322dac233..75896602e732 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -7195,7 +7195,6 @@ static pci_ers_result_t e1000_io_slot_reset(struct pci_dev *pdev) "Cannot re-enable PCI device after reset.\n"); result = PCI_ERS_RESULT_DISCONNECT; } else { - pdev->state_saved = true; pci_restore_state(pdev); pci_set_master(pdev); diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c index ae5fe34659cf..d75b8a50413d 100644 --- a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c +++ b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c @@ -2423,12 +2423,6 @@ static pci_ers_result_t fm10k_io_slot_reset(struct pci_dev *pdev) } else { pci_set_master(pdev); pci_restore_state(pdev); - - /* After second error pci->state_saved is false, this - * resets it so EEH doesn't break. - */ - pci_save_state(pdev); - pci_wake_from_d3(pdev, false); result = PCI_ERS_RESULT_RECOVERED; diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 50be0a60ae13..d8192aa23254 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -16455,7 +16455,6 @@ static pci_ers_result_t i40e_pci_error_slot_reset(struct pci_dev *pdev) } else { pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); pci_wake_from_d3(pdev, false); reg = rd32(&pf->hw, I40E_GLGEN_RTRIG); diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c index 86f5859e88ef..6c7dcca7bc44 100644 --- a/drivers/net/ethernet/intel/ice/ice_main.c +++ b/drivers/net/ethernet/intel/ice/ice_main.c @@ -5663,7 +5663,6 @@ static int ice_resume(struct device *dev) pci_set_power_state(pdev, PCI_D0); pci_restore_state(pdev); - pci_save_state(pdev); if (!pci_device_is_present(pdev)) return -ENODEV; @@ -5763,7 +5762,6 @@ static pci_ers_result_t ice_pci_err_slot_reset(struct pci_dev *pdev) } else { pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); pci_wake_from_d3(pdev, false); /* Check for life */ diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 85f9589cc568..dbea37269d2c 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -9599,7 +9599,6 @@ static int __igb_resume(struct device *dev, bool rpm) pci_set_power_state(pdev, PCI_D0); pci_restore_state(pdev); - pci_save_state(pdev); if (!pci_device_is_present(pdev)) return -ENODEV; @@ -9754,7 +9753,6 @@ static pci_ers_result_t igb_io_slot_reset(struct pci_dev *pdev) } else { pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); pci_enable_wake(pdev, PCI_D3hot, 0); pci_enable_wake(pdev, PCI_D3cold, 0); diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 728d7ca5338b..7aafa60ba0c8 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -7530,7 +7530,6 @@ static int __igc_resume(struct device *dev, bool rpm) pci_set_power_state(pdev, PCI_D0); pci_restore_state(pdev); - pci_save_state(pdev); if (!pci_device_is_present(pdev)) return -ENODEV; @@ -7667,7 +7666,6 @@ static pci_ers_result_t igc_io_slot_reset(struct pci_dev *pdev) } else { pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); pci_enable_wake(pdev, PCI_D3hot, 0); pci_enable_wake(pdev, PCI_D3cold, 0); diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 90d4e57b1c93..d65d691ac961 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -12297,7 +12297,6 @@ static pci_ers_result_t ixgbe_io_slot_reset(struct pci_dev *pdev) adapter->hw.hw_addr = adapter->io_addr; pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); pci_wake_from_d3(pdev, false); diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c index 03d2fc7d9b09..d1fbf37bdaf7 100644 --- a/drivers/net/ethernet/mellanox/mlx4/main.c +++ b/drivers/net/ethernet/mellanox/mlx4/main.c @@ -4366,7 +4366,6 @@ static pci_ers_result_t mlx4_pci_slot_reset(struct pci_dev *pdev) pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); return PCI_ERS_RESULT_RECOVERED; } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c b/drivers/net/ethernet/mellanox/mlx5/core/main.c index df93625c9dfa..08f777836a8b 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c @@ -2095,7 +2095,6 @@ static pci_ers_result_t mlx5_pci_slot_reset(struct pci_dev *pdev) pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); err = wait_vital(pdev); if (err) { diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_pci.c b/drivers/net/ethernet/meta/fbnic/fbnic_pci.c index a7a6b4db8016..0fa90baad5f8 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_pci.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_pci.c @@ -574,7 +574,6 @@ static pci_ers_result_t fbnic_err_slot_reset(struct pci_dev *pdev) pci_set_power_state(pdev, PCI_D0); pci_restore_state(pdev); - pci_save_state(pdev); if (pci_enable_device_mem(pdev)) { dev_err(&pdev->dev, diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c index 9d70b51ca91d..e4c542fc6c2b 100644 --- a/drivers/net/ethernet/microchip/lan743x_main.c +++ b/drivers/net/ethernet/microchip/lan743x_main.c @@ -3915,7 +3915,6 @@ static int lan743x_pm_resume(struct device *dev) pci_set_power_state(pdev, PCI_D0); pci_restore_state(pdev); - pci_save_state(pdev); /* Restore HW_CFG that was saved during pm suspend */ if (adapter->is_pci11x1x) diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c index e611ff7fa3fa..7be30a8df268 100644 --- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c +++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c @@ -3416,10 +3416,6 @@ static void myri10ge_watchdog(struct work_struct *work) * nic was resumed from power saving mode. */ pci_restore_state(mgp->pdev); - - /* save state again for accounting reasons */ - pci_save_state(mgp->pdev); - } else { /* if we get back -1's from our slot, perhaps somebody * powered off our card. Don't try to reset it in diff --git a/drivers/net/ethernet/neterion/s2io.c b/drivers/net/ethernet/neterion/s2io.c index 5026b0263d43..1e55ccb4822b 100644 --- a/drivers/net/ethernet/neterion/s2io.c +++ b/drivers/net/ethernet/neterion/s2io.c @@ -3425,7 +3425,6 @@ static void s2io_reset(struct s2io_nic *sp) /* Restore the PCI state saved during initialization. */ pci_restore_state(sp->pdev); - pci_save_state(sp->pdev); pci_read_config_word(sp->pdev, 0x2, &val16); if (check_pci_device_id(val16) != (u16)PCI_ANY_ID) break; diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c index d1b68c18444f..38a41ccf79b9 100644 --- a/drivers/pci/pcie/portdrv.c +++ b/drivers/pci/pcie/portdrv.c @@ -760,7 +760,6 @@ static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev) device_for_each_child(&dev->dev, &off, pcie_port_device_iter); pci_restore_state(dev); - pci_save_state(dev); return PCI_ERS_RESULT_RECOVERED; } diff --git a/drivers/scsi/bfa/bfad.c b/drivers/scsi/bfa/bfad.c index ff9adfc0b332..bdfd06516671 100644 --- a/drivers/scsi/bfa/bfad.c +++ b/drivers/scsi/bfa/bfad.c @@ -1528,7 +1528,6 @@ bfad_pci_slot_reset(struct pci_dev *pdev) goto out_disable_device; } - pci_save_state(pdev); pci_set_master(pdev); rc = dma_set_mask_and_coherent(&bfad->pcidev->dev, DMA_BIT_MASK(64)); diff --git a/drivers/scsi/csiostor/csio_init.c b/drivers/scsi/csiostor/csio_init.c index 79c8dafdd49e..db0c2174430a 100644 --- a/drivers/scsi/csiostor/csio_init.c +++ b/drivers/scsi/csiostor/csio_init.c @@ -1093,7 +1093,6 @@ csio_pci_slot_reset(struct pci_dev *pdev) pci_set_master(pdev); pci_restore_state(pdev); - pci_save_state(pdev); /* Bring HW s/m to ready state. * but don't resume IOs. diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c index 44214884deaf..95123689e9d1 100644 --- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -7859,7 +7859,6 @@ static int ipr_reset_restore_cfg_space(struct ipr_cmnd *ipr_cmd) struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg; ENTER; - ioa_cfg->pdev->state_saved = true; pci_restore_state(ioa_cfg->pdev); if (ipr_set_pcix_cmd_reg(ioa_cfg)) { diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c index f206267d9ecd..065eb91de9c0 100644 --- a/drivers/scsi/lpfc/lpfc_init.c +++ b/drivers/scsi/lpfc/lpfc_init.c @@ -14434,12 +14434,6 @@ lpfc_io_slot_reset_s3(struct pci_dev *pdev) pci_restore_state(pdev); - /* - * As the new kernel behavior of pci_restore_state() API call clears - * device saved_state flag, need to save the restored state again. - */ - pci_save_state(pdev); - if (pdev->is_busmaster) pci_set_master(pdev); diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c index 5ffd94586652..9007533e36e0 100644 --- a/drivers/scsi/qla2xxx/qla_os.c +++ b/drivers/scsi/qla2xxx/qla_os.c @@ -7886,11 +7886,6 @@ qla2xxx_pci_slot_reset(struct pci_dev *pdev) pci_restore_state(pdev); - /* pci_restore_state() clears the saved_state flag of the device - * save restored state which resets saved_state flag - */ - pci_save_state(pdev); - if (ha->mem_only) rc = pci_enable_device_mem(pdev); else diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c index a761c0aa5127..1f52379bc0b5 100644 --- a/drivers/scsi/qla4xxx/ql4_os.c +++ b/drivers/scsi/qla4xxx/ql4_os.c @@ -9796,11 +9796,6 @@ qla4xxx_pci_slot_reset(struct pci_dev *pdev) */ pci_restore_state(pdev); - /* pci_restore_state() clears the saved_state flag of the device - * save restored state which resets saved_state flag - */ - pci_save_state(pdev); - /* Initialize device or resume if in suspended state */ rc = pci_enable_device(pdev); if (rc) { diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 152f914c599d..65bd370f282a 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -6178,7 +6178,6 @@ static pci_ers_result_t serial8250_io_slot_reset(struct pci_dev *dev) return PCI_ERS_RESULT_DISCONNECT; pci_restore_state(dev); - pci_save_state(dev); return PCI_ERS_RESULT_RECOVERED; } diff --git a/drivers/tty/serial/jsm/jsm_driver.c b/drivers/tty/serial/jsm/jsm_driver.c index 417a5b6bffc3..8d21373cae57 100644 --- a/drivers/tty/serial/jsm/jsm_driver.c +++ b/drivers/tty/serial/jsm/jsm_driver.c @@ -355,7 +355,6 @@ static void jsm_io_resume(struct pci_dev *pdev) struct jsm_board *brd = pci_get_drvdata(pdev); pci_restore_state(pdev); - pci_save_state(pdev); jsm_uart_port_init(brd); } From 5e09895b4063e9f57c6fc416cf30cd0c6ca7ec74 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Fri, 21 Nov 2025 18:31:17 +0100 Subject: [PATCH 5/5] Documentation: PCI: Amend error recovery doc with pci_save_state() rules After recovering from a PCI error through reset, affected devices are in D0_uninitialized state and need to be brought into D0_active state by re-initializing their Config Space registers (PCIe r7.0 sec 5.3.1.1). To facilitate that, the PCI core provides pci_restore_state() and pci_save_state() helpers. Document rules governing their usage. As Bjorn notes, so far no file in "Documentation/ includes anything about the idea of a driver using pci_save_state() to capture the state it wants to restore after an error", even though it is a common pattern in drivers. So that's obviously a gap that should be closed. Reported-by: Bjorn Helgaas Closes: https://lore.kernel.org/r/20251113161556.GA2284238@bhelgaas/ Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki (Intel) Link: https://patch.msgid.link/077596ba70202be0e43fdad3bb9b93d356cbe4ec.1763746079.git.lukas@wunner.de --- Documentation/PCI/pci-error-recovery.rst | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/PCI/pci-error-recovery.rst b/Documentation/PCI/pci-error-recovery.rst index 5df481ac6193..43bc4e3665b4 100644 --- a/Documentation/PCI/pci-error-recovery.rst +++ b/Documentation/PCI/pci-error-recovery.rst @@ -326,6 +326,21 @@ be recovered, there is nothing more that can be done; the platform will typically report a "permanent failure" in such a case. The device will be considered "dead" in this case. +Drivers typically need to call pci_restore_state() after reset to +re-initialize the device's config space registers and thereby +bring it from D0\ :sub:`uninitialized` into D0\ :sub:`active` state +(PCIe r7.0 sec 5.3.1.1). The PCI core invokes pci_save_state() +on enumeration after initializing config space to ensure that a +saved state is available for subsequent error recovery. +Drivers which modify config space on probe may need to invoke +pci_save_state() afterwards to record those changes for later +error recovery. When going into system suspend, pci_save_state() +is called for every PCI device and that state will be restored +not only on resume, but also on any subsequent error recovery. +In the unlikely event that the saved state recorded on suspend +is unsuitable for error recovery, drivers should call +pci_save_state() on resume. + Drivers for multi-function cards will need to coordinate among themselves as to which driver instance will perform any "one-shot" or global device initialization. For example, the Symbios sym53cxx2