> -----Original Message-----
> From: [email protected] <[email protected]>
> Sent: Friday, November 14, 2025 9:29 PM
> To: KY Srinivasan <[email protected]>; Haiyang Zhang
> <[email protected]>; Wei Liu <[email protected]>; Dexuan Cui
> <[email protected]>; David S. Miller <[email protected]>; Eric Dumazet
> <[email protected]>; Jakub Kicinski <[email protected]>; Paolo Abeni
> <[email protected]>; Shradha Gupta <[email protected]>;
> Simon Horman <[email protected]>; Konstantin Taranov
> <[email protected]>; Souradeep Chakrabarti
> <[email protected]>; Erick Archer
> <[email protected]>; [email protected];
> [email protected]; [email protected]; linux-
> [email protected]
> Cc: Long Li <[email protected]>
> Subject: [patch net-next] net: mana: Handle hardware reset events when
> probing the device
>
> From: Long Li <[email protected]>
>
> When MANA is being probed, it's possible that hardware is in recovery
> mode and the device may get GDMA_EQE_HWC_RESET_REQUEST over HWC in the
> middle of the probe. Detect such condition and go through the recovery
> service procedure.
>
> Fixes: fbe346ce9d62 ("net: mana: Handle Reset Request from MANA NIC")
> Signed-off-by: Long Li <[email protected]>
> ---
> .../net/ethernet/microsoft/mana/gdma_main.c | 131 +++++++++++++++---
> include/net/mana/gdma.h | 9 +-
> 2 files changed, 122 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c
> b/drivers/net/ethernet/microsoft/mana/gdma_main.c
> index effe0a2f207a..1d9c2beb22b2 100644
> --- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
> +++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
> @@ -15,6 +15,12 @@
>
> struct dentry *mana_debugfs_root;
>
> +static struct mana_serv_delayed_work {
> + struct delayed_work work;
> + struct pci_dev *pdev;
> + enum gdma_eqe_type type;
> +} mns_delayed_wk;
> +
> static u32 mana_gd_r32(struct gdma_context *g, u64 offset)
> {
> return readl(g->bar0_va + offset);
> @@ -387,6 +393,25 @@ EXPORT_SYMBOL_NS(mana_gd_ring_cq, "NET_MANA");
>
> #define MANA_SERVICE_PERIOD 10
>
> +static void mana_serv_rescan(struct pci_dev *pdev)
> +{
> + struct pci_bus *parent;
> +
> + pci_lock_rescan_remove();
> +
> + parent = pdev->bus;
> + if (!parent) {
> + dev_err(&pdev->dev, "MANA service: no parent bus\n");
> + goto out;
> + }
> +
> + pci_stop_and_remove_bus_device(pdev);
> + pci_rescan_bus(parent);
> +
> +out:
> + pci_unlock_rescan_remove();
> +}
> +
> static void mana_serv_fpga(struct pci_dev *pdev)
> {
> struct pci_bus *bus, *parent;
> @@ -419,9 +444,12 @@ static void mana_serv_reset(struct pci_dev *pdev)
> {
> struct gdma_context *gc = pci_get_drvdata(pdev);
> struct hw_channel_context *hwc;
> + int ret;
>
> if (!gc) {
> - dev_err(&pdev->dev, "MANA service: no GC\n");
> + /* Perform PCI rescan on device if GC is not set up */
> + dev_err(&pdev->dev, "MANA service: GC not setup,
> rescanning\n");
> + mana_serv_rescan(pdev);
> return;
> }
>
> @@ -440,9 +468,18 @@ static void mana_serv_reset(struct pci_dev *pdev)
>
> msleep(MANA_SERVICE_PERIOD * 1000);
>
> - mana_gd_resume(pdev);
> + ret = mana_gd_resume(pdev);
> + if (ret == -ETIMEDOUT || ret == -EPROTO) {
> + /* Perform PCI rescan on device if we failed on HWC */
> + dev_err(&pdev->dev, "MANA service: resume failed,
> rescanning\n");
> + mana_serv_rescan(pdev);
> + goto out;
> + }
>
> - dev_info(&pdev->dev, "MANA reset cycle completed\n");
> + if (ret)
> + dev_info(&pdev->dev, "MANA reset cycle failed err %d\n", ret);
> + else
> + dev_info(&pdev->dev, "MANA reset cycle completed\n");
>
> out:
> gc->in_service = false;
> @@ -454,18 +491,9 @@ struct mana_serv_work {
> enum gdma_eqe_type type;
> };
>
> -static void mana_serv_func(struct work_struct *w)
> +static void mana_do_service(enum gdma_eqe_type type, struct pci_dev
> *pdev)
> {
> - struct mana_serv_work *mns_wk;
> - struct pci_dev *pdev;
> -
> - mns_wk = container_of(w, struct mana_serv_work, serv_work);
> - pdev = mns_wk->pdev;
> -
> - if (!pdev)
> - goto out;
> -
> - switch (mns_wk->type) {
> + switch (type) {
> case GDMA_EQE_HWC_FPGA_RECONFIG:
> mana_serv_fpga(pdev);
> break;
> @@ -475,12 +503,36 @@ static void mana_serv_func(struct work_struct *w)
> break;
>
> default:
> - dev_err(&pdev->dev, "MANA service: unknown type %d\n",
> - mns_wk->type);
> + dev_err(&pdev->dev, "MANA service: unknown type %d\n", type);
> break;
> }
> +}
> +
> +static void mana_serv_delayed_func(struct work_struct *w)
> +{
> + struct mana_serv_delayed_work *dwork;
> + struct pci_dev *pdev;
> +
> + dwork = container_of(w, struct mana_serv_delayed_work, work.work);
> + pdev = dwork->pdev;
> +
> + if (pdev)
> + mana_do_service(dwork->type, pdev);
> +
> + pci_dev_put(pdev);
> +}
> +
> +static void mana_serv_func(struct work_struct *w)
> +{
> + struct mana_serv_work *mns_wk;
> + struct pci_dev *pdev;
> +
> + mns_wk = container_of(w, struct mana_serv_work, serv_work);
> + pdev = mns_wk->pdev;
> +
> + if (pdev)
> + mana_do_service(mns_wk->type, pdev);
>
> -out:
> pci_dev_put(pdev);
> kfree(mns_wk);
> module_put(THIS_MODULE);
> @@ -541,6 +593,17 @@ static void mana_gd_process_eqe(struct gdma_queue
> *eq)
> case GDMA_EQE_HWC_RESET_REQUEST:
> dev_info(gc->dev, "Recv MANA service type:%d\n", type);
>
> + if (atomic_inc_return(&gc->in_probe) == 1) {
Since we don't care about how many times it entered probe/service,
test_and_set_bit() should be sufficient here.
> + /*
> + * Device is in probe and we received an hardware reset
> + * event, probe() will detect that "in_probe" has
> + * changed and perform service procedure.
> + */
> + dev_info(gc->dev,
> + "Service is to be processed in probe\n");
> + break;
> + }
> +
> if (gc->in_service) {
> dev_info(gc->dev, "Already in service\n");
> break;
> @@ -1930,6 +1993,8 @@ static int mana_gd_probe(struct pci_dev *pdev, const
> struct pci_device_id *ent)
> gc->mana_pci_debugfs = debugfs_create_dir(pci_slot_name(pdev-
> >slot),
> mana_debugfs_root);
>
> + atomic_set(&gc->in_probe, 0);
> +
> err = mana_gd_setup(pdev);
> if (err)
> goto unmap_bar;
> @@ -1942,8 +2007,19 @@ static int mana_gd_probe(struct pci_dev *pdev,
> const struct pci_device_id *ent)
> if (err)
> goto cleanup_mana;
>
> + /*
> + * If a hardware reset event has occurred over HWC during probe,
> + * rollback and perform hardware reset procedure.
> + */
> + if (atomic_inc_return(&gc->in_probe) > 1) {
> + err = -EPROTO;
> + goto cleanup_mana_rdma;
> + }
> +
> return 0;
>
> +cleanup_mana_rdma:
> + mana_rdma_remove(&gc->mana_ib);
> cleanup_mana:
> mana_remove(&gc->mana, false);
> cleanup_gd:
> @@ -1967,6 +2043,25 @@ static int mana_gd_probe(struct pci_dev *pdev,
> const struct pci_device_id *ent)
> disable_dev:
> pci_disable_device(pdev);
> dev_err(&pdev->dev, "gdma probe failed: err = %d\n", err);
> +
> + /*
> + * Hardware could be in recovery mode and the HWC returns TIMEDOUT
> or
> + * EPROTO from mana_gd_setup(), mana_probe() or mana_rdma_probe(),
> or
> + * we received a hardware reset event over HWC interrupt. In this
> case,
> + * perform the device recovery procedure after MANA_SERVICE_PERIOD
> + * seconds.
> + */
> + if (err == -ETIMEDOUT || err == -EPROTO) {
> + dev_info(&pdev->dev, "Start MANA recovery mode\n");
> +
> + mns_delayed_wk.pdev = pci_dev_get(pdev);
> + mns_delayed_wk.type = GDMA_EQE_HWC_RESET_REQUEST;
> +
> + INIT_DELAYED_WORK(&mns_delayed_wk.work,
> mana_serv_delayed_func);
To avoid INIT_DELAYED_WORK potentially multiple times this should be in
the mana_driver_init()
> + schedule_delayed_work(&mns_delayed_wk.work,
> + secs_to_jiffies(MANA_SERVICE_PERIOD));
> + }
> +
> return err;
> }
>
> @@ -2084,6 +2179,8 @@ static int __init mana_driver_init(void)
>
> static void __exit mana_driver_exit(void)
> {
> + cancel_delayed_work_sync(&mns_delayed_wk.work);
I think we should call disable_delayed_work_sync() to prevent the work
scheduled again after this line.
> +
> pci_unregister_driver(&mana_driver);
>
> debugfs_remove(mana_debugfs_root);
> diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
> index 637f42485dba..1bb4c6ada2b6 100644
> --- a/include/net/mana/gdma.h
> +++ b/include/net/mana/gdma.h
> @@ -430,6 +430,9 @@ struct gdma_context {
> u64 pf_cap_flags1;
>
> struct workqueue_struct *service_wq;
> +
> + /* Count how many times we have finished probe or HWC events */
> + atomic_t in_probe;
> };
>
> static inline bool mana_gd_is_mana(struct gdma_dev *gd)
> @@ -592,6 +595,9 @@ enum {
> #define GDMA_DRV_CAP_FLAG_1_HANDLE_RECONFIG_EQE BIT(17)
> #define GDMA_DRV_CAP_FLAG_1_HW_VPORT_LINK_AWARE BIT(6)
>
> +/* Driver can handle hardware reset events during probe */
> +#define GDMA_DRV_CAP_FLAG_1_RECOVER_PROBE BIT(22)
> +
> #define GDMA_DRV_CAP_FLAGS1 \
> (GDMA_DRV_CAP_FLAG_1_EQ_SHARING_MULTI_VPORT | \
> GDMA_DRV_CAP_FLAG_1_NAPI_WKDONE_FIX | \
> @@ -601,7 +607,8 @@ enum {
> GDMA_DRV_CAP_FLAG_1_DYNAMIC_IRQ_ALLOC_SUPPORT | \
> GDMA_DRV_CAP_FLAG_1_SELF_RESET_ON_EQE | \
> GDMA_DRV_CAP_FLAG_1_HANDLE_RECONFIG_EQE | \
> - GDMA_DRV_CAP_FLAG_1_HW_VPORT_LINK_AWARE)
> + GDMA_DRV_CAP_FLAG_1_HW_VPORT_LINK_AWARE | \
> + GDMA_DRV_CAP_FLAG_1_RECOVER_PROBE)
>
> #define GDMA_DRV_CAP_FLAGS2 0
>
> --
> 2.43.0
