The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <sta...@vger.kernel.org>.
Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 002bf2fbc00e5c4b95fb167287e2ae7d1973281e Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka <stanislaw.grus...@linux.intel.com> Date: Mon, 12 Feb 2024 13:01:35 +0100 Subject: [PATCH] PCI/AER: Block runtime suspend when handling errors PM runtime can be done simultaneously with AER error handling. Avoid that by using pm_runtime_get_sync() before and pm_runtime_put() after reset in pcie_do_recovery() for all recovering devices. pm_runtime_get_sync() will increase dev->power.usage_count counter to prevent any possible future request to runtime suspend a device. It will also resume a device, if it was previously in D3hot state. I tested with igc device by doing simultaneous aer_inject and rpm suspend/resume via /sys/bus/pci/devices/PCI_ID/power/control and can reproduce: igc 0000:02:00.0: not ready 65535ms after bus reset; giving up pcieport 0000:00:1c.2: AER: Root Port link has been reset (-25) pcieport 0000:00:1c.2: AER: subordinate device reset failed pcieport 0000:00:1c.2: AER: device recovery failed igc 0000:02:00.0: Unable to change power state from D3hot to D0, device inaccessible The problem disappears when this patch is applied. Link: https://lore.kernel.org/r/20240212120135.146068-1-stanislaw.grus...@linux.intel.com Signed-off-by: Stanislaw Gruszka <stanislaw.grus...@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelg...@google.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppusw...@linux.intel.com> Acked-by: Rafael J. Wysocki <raf...@kernel.org> Cc: <sta...@vger.kernel.org> --- drivers/pci/pcie/err.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c index 59c90d04a609a..705893b5f7b09 100644 --- a/drivers/pci/pcie/err.c +++ b/drivers/pci/pcie/err.c @@ -13,6 +13,7 @@ #define dev_fmt(fmt) "AER: " fmt #include <linux/pci.h> +#include <linux/pm_runtime.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/errno.h> @@ -85,6 +86,18 @@ static int report_error_detected(struct pci_dev *dev, return 0; } +static int pci_pm_runtime_get_sync(struct pci_dev *pdev, void *data) +{ + pm_runtime_get_sync(&pdev->dev); + return 0; +} + +static int pci_pm_runtime_put(struct pci_dev *pdev, void *data) +{ + pm_runtime_put(&pdev->dev); + return 0; +} + static int report_frozen_detected(struct pci_dev *dev, void *data) { return report_error_detected(dev, pci_channel_io_frozen, data); @@ -207,6 +220,8 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, else bridge = pci_upstream_bridge(dev); + pci_walk_bridge(bridge, pci_pm_runtime_get_sync, NULL); + pci_dbg(bridge, "broadcast error_detected message\n"); if (state == pci_channel_io_frozen) { pci_walk_bridge(bridge, report_frozen_detected, &status); @@ -251,10 +266,15 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, pcie_clear_device_status(dev); pci_aer_clear_nonfatal_status(dev); } + + pci_walk_bridge(bridge, pci_pm_runtime_put, NULL); + pci_info(bridge, "device recovery successful\n"); return status; failed: + pci_walk_bridge(bridge, pci_pm_runtime_put, NULL); + pci_uevent_ers(bridge, PCI_ERS_RESULT_DISCONNECT); /* TODO: Should kernel panic here? */ -- 2.43.0
