Hi Sadhasivam, > -----Original Message----- > From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> > Sent: Tuesday, January 21, 2025 10:18 AM > To: Havalige, Thippeswamy <thippeswamy.havalige@xxxxxxx> > Cc: bhelgaas@xxxxxxxxxx; lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx; robh@xxxxxxxxxx; > krzk+dt@xxxxxxxxxx; conor+dt@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; jingoohan1@xxxxxxxxx; > Simek, Michal <michal.simek@xxxxxxx>; Gogada, Bharat Kumar > <bharat.kumar.gogada@xxxxxxx> > Subject: Re: [PATCH v7 3/3] PCI: amd-mdb: Add AMD MDB Root Port driver > > On Mon, Jan 20, 2025 at 04:13:05AM +0530, Thippeswamy Havalige wrote: > > Add support for AMD MDB (Multimedia DMA Bridge) IP core as Root Port. > > > > The Versal2 devices include MDB Module. The integrated block for MDB > > along with the integrated bridge can function as PCIe Root Port > > controller at > > Gen5 32-Gb/s operation per lane. > > > > Bridge supports error and legacy interrupts and are handled using > > platform specific interrupt line in Versal2. > > > > Signed-off-by: Thippeswamy Havalige <thippeswamy.havalige@xxxxxxx> > > --- > > changes in v2: > > ------------- > > - Update Gen5 speed in the patch description. > > - Modify Kconfig file. > > - Update string _leg_ to intx. > > - Get platform structure through automic variables. > > - Remove _rp_ in function. > > Changes in v3: > > -------------- > > -None. > > Changes in v4: > > -------------- > > -None. > > Changes in v5: > > -------------- > > -None. > > Changes in v6: > > -------------- > > - Remove pdev automatic variable. > > - Update register name to slcr. > > - Fix whitespace. > > - remove Spurious extra line. > > - Update Legacy to INTx. > > - Add space before (SLCR). > > - Update menuconfig description. > > --- > > drivers/pci/controller/dwc/Kconfig | 11 + > > drivers/pci/controller/dwc/Makefile | 1 + > > drivers/pci/controller/dwc/pcie-amd-mdb.c | 436 > > ++++++++++++++++++++++ > > 3 files changed, 448 insertions(+) > > create mode 100644 drivers/pci/controller/dwc/pcie-amd-mdb.c > > > > diff --git a/drivers/pci/controller/dwc/Kconfig > > b/drivers/pci/controller/dwc/Kconfig > > index b6d6778b0698..61d119646749 100644 > > --- a/drivers/pci/controller/dwc/Kconfig > > +++ b/drivers/pci/controller/dwc/Kconfig > > @@ -27,6 +27,17 @@ config PCIE_AL > > required only for DT-based platforms. ACPI platforms with the > > Annapurna Labs PCIe controller don't need to enable this. > > > > +config PCIE_AMD_MDB > > + bool "AMD MDB Versal2 PCIe Host controller" > > + depends on OF || COMPILE_TEST > > + depends on PCI && PCI_MSI > > + select PCIE_DW_HOST > > + help > > + Say Y here if you want to enable PCIe controller support on AMD > > + Versal2 SoCs. The AMD MDB Versal2 PCIe controller is based on > DesignWare > > + IP and therefore the driver re-uses the Designware core functions to > > + implement the driver. > > + > > config PCI_MESON > > tristate "Amlogic Meson PCIe controller" > > default m if ARCH_MESON > > diff --git a/drivers/pci/controller/dwc/Makefile > > b/drivers/pci/controller/dwc/Makefile > > index a8308d9ea986..ae27eda6ec5e 100644 > > --- a/drivers/pci/controller/dwc/Makefile > > +++ b/drivers/pci/controller/dwc/Makefile > > @@ -3,6 +3,7 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o > > obj-$(CONFIG_PCIE_DW_HOST) += pcie-designware-host.o > > obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o > > obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o > > +obj-$(CONFIG_PCIE_AMD_MDB) += pcie-amd-mdb.o > > obj-$(CONFIG_PCIE_BT1) += pcie-bt1.o > > obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o > > obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o diff --git > > a/drivers/pci/controller/dwc/pcie-amd-mdb.c > > b/drivers/pci/controller/dwc/pcie-amd-mdb.c > > new file mode 100644 > > index 000000000000..ef1ac757d41c > > --- /dev/null > > +++ b/drivers/pci/controller/dwc/pcie-amd-mdb.c > > @@ -0,0 +1,436 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * PCIe host controller driver for AMD MDB PCIe Bridge > > + * > > + * Copyright (C) 2024-2025, Advanced Micro Devices, Inc. > > + */ > > + > > +#include <linux/clk.h> > > +#include <linux/delay.h> > > +#include <linux/gpio.h> > > +#include <linux/interrupt.h> > > +#include <linux/irqdomain.h> > > +#include <linux/kernel.h> > > +#include <linux/init.h> > > +#include <linux/of_device.h> > > +#include <linux/pci.h> > > +#include <linux/platform_device.h> > > +#include <linux/resource.h> > > +#include <linux/types.h> > > + > > +#include "pcie-designware.h" > > + > > +#define AMD_MDB_TLP_IR_STATUS_MISC 0x4C0 > > +#define AMD_MDB_TLP_IR_MASK_MISC 0x4C4 > > +#define AMD_MDB_TLP_IR_ENABLE_MISC 0x4C8 > > + > > +#define AMD_MDB_PCIE_IDRN_SHIFT 16 > > + > > +/* Interrupt registers definitions */ > > +#define AMD_MDB_PCIE_INTR_CMPL_TIMEOUT 15 > > +#define AMD_MDB_PCIE_INTR_PM_PME_RCVD 24 > > +#define AMD_MDB_PCIE_INTR_PME_TO_ACK_RCVD 25 > > +#define AMD_MDB_PCIE_INTR_MISC_CORRECTABLE 26 > > +#define AMD_MDB_PCIE_INTR_NONFATAL 27 > > +#define AMD_MDB_PCIE_INTR_FATAL 28 > > + > > +#define IMR(x) BIT(AMD_MDB_PCIE_INTR_ ##x) > > +#define AMD_MDB_PCIE_IMR_ALL_MASK \ > > + ( \ > > + IMR(CMPL_TIMEOUT) | \ > > + IMR(PM_PME_RCVD) | \ > > + IMR(PME_TO_ACK_RCVD) | \ > > + IMR(MISC_CORRECTABLE) | \ > > + IMR(NONFATAL) | \ > > + IMR(FATAL) \ > > + ) > > + > > +/** > > + * struct amd_mdb_pcie - PCIe port information > > + * @pci: DesignWare PCIe controller structure > > + * @slcr: MDB System Level Control and Status Register (SLCR) Base > > + * @intx_domain: INTx IRQ domain pointer > > + * @mdb_domain: MDB IRQ domain pointer */ struct amd_mdb_pcie { > > + struct dw_pcie pci; > > + void __iomem *slcr; > > + struct irq_domain *intx_domain; > > + struct irq_domain *mdb_domain; > > +}; > > + > > +static const struct dw_pcie_host_ops amd_mdb_pcie_host_ops = { }; > > + > > +static inline u32 pcie_read(struct amd_mdb_pcie *pcie, u32 reg) > > No need of 'inline' keyword in .c files. Compiler will inline the function on its own > when required. > > But I'd prefer to use the {readl/writel}_relaxed directly instead of a wrapper. - Thank you for reviewing, Will remove inline keyword & like to keep wrapper function. > > > +{ > > + return readl_relaxed(pcie->slcr + reg); } > > + > > +static inline void pcie_write(struct amd_mdb_pcie *pcie, > > + u32 val, u32 reg) > > +{ > > + writel_relaxed(val, pcie->slcr + reg); } > > + > > +static void amd_mdb_mask_intx_irq(struct irq_data *data) { > > + struct amd_mdb_pcie *pcie = irq_data_get_irq_chip_data(data); > > + struct dw_pcie *pci = &pcie->pci; > > + struct dw_pcie_rp *port = &pci->pp; > > + unsigned long flags; > > + u32 mask, val; > > + > > + mask = BIT(data->hwirq + AMD_MDB_PCIE_IDRN_SHIFT); > > + raw_spin_lock_irqsave(&port->lock, flags); > > + > > Remove the newline here and add it before raw_spin_lock_irqsave(). - Thank you for review comments, Will remove this piece of call back function. > > > + val = pcie_read(pcie, AMD_MDB_TLP_IR_STATUS_MISC); > > + pcie_write(pcie, (val & (~mask)), AMD_MDB_TLP_IR_STATUS_MISC); > > + > > Remove the newline here. - Thank you for review comments, Will remove this piece of call back function. > > > + raw_spin_unlock_irqrestore(&port->lock, flags); } > > + > > +static void amd_mdb_unmask_intx_irq(struct irq_data *data) { > > + struct amd_mdb_pcie *pcie = irq_data_get_irq_chip_data(data); > > + struct dw_pcie *pci = &pcie->pci; > > + struct dw_pcie_rp *port = &pci->pp; > > + unsigned long flags; > > + u32 mask; > > + u32 val; > > + > > + mask = BIT(data->hwirq + AMD_MDB_PCIE_IDRN_SHIFT); > > + raw_spin_lock_irqsave(&port->lock, flags); > > + > > Same as above. > > > + val = pcie_read(pcie, AMD_MDB_TLP_IR_STATUS_MISC); > > + pcie_write(pcie, (val | mask), AMD_MDB_TLP_IR_STATUS_MISC); > > + > > + raw_spin_unlock_irqrestore(&port->lock, flags); } > > + > > +static struct irq_chip amd_mdb_intx_irq_chip = { > > + .name = "INTx", > > Add the 'AMD MDB' prefix. - Thank you for review comments, Will remove this piece of call back function. > > > + .irq_mask = amd_mdb_mask_intx_irq, > > + .irq_unmask = amd_mdb_unmask_intx_irq, > > +}; > > + > > +/** > > + * amd_mdb_pcie_intx_map - Set the handler for the INTx and mark IRQ > > + * as valid > > + * @domain: IRQ domain > > + * @irq: Virtual IRQ number > > + * @hwirq: HW interrupt number > > + * > > + * Return: Always returns 0. > > + */ > > +static int amd_mdb_pcie_intx_map(struct irq_domain *domain, > > + unsigned int irq, irq_hw_number_t hwirq) { > > + irq_set_chip_and_handler(irq, &amd_mdb_intx_irq_chip, > > + handle_level_irq); > > + irq_set_chip_data(irq, domain->host_data); > > + irq_set_status_flags(irq, IRQ_LEVEL); > > + > > + return 0; > > +} > > + > > +/* INTx IRQ Domain operations */ > > +static const struct irq_domain_ops amd_intx_domain_ops = { > > + .map = amd_mdb_pcie_intx_map, > > +}; > > + > > +/** > > + * amd_mdb_pcie_init_port - Initialize hardware > > + * @pcie: PCIe port information > > + */ > > This kernel doc doesn't add any value. So you can drop it. - Thank you for review comments, Will remove this kernel doc in next patch. > > > +static int amd_mdb_pcie_init_port(struct amd_mdb_pcie *pcie) { > > + int val; > > + > > + /* Disable all TLP Interrupts */ > > + pcie_write(pcie, pcie_read(pcie, AMD_MDB_TLP_IR_ENABLE_MISC) & > > + ~AMD_MDB_PCIE_IMR_ALL_MASK, > > + AMD_MDB_TLP_IR_ENABLE_MISC); > > + > > + /* Clear pending TLP interrupts */ > > + pcie_write(pcie, pcie_read(pcie, AMD_MDB_TLP_IR_STATUS_MISC) & > > + AMD_MDB_PCIE_IMR_ALL_MASK, > > + AMD_MDB_TLP_IR_STATUS_MISC); > > + > > + /* Enable all TLP Interrupts */ > > + val = pcie_read(pcie, AMD_MDB_TLP_IR_ENABLE_MISC); > > + pcie_write(pcie, (val | AMD_MDB_PCIE_IMR_ALL_MASK), > > + AMD_MDB_TLP_IR_ENABLE_MISC); > > + > > + return 0; > > +} > > + > > +static irqreturn_t amd_mdb_pcie_event_flow(int irq, void *args) { > > + struct amd_mdb_pcie *pcie = args; > > + unsigned long val; > > + int i; > > + > > + val = pcie_read(pcie, AMD_MDB_TLP_IR_STATUS_MISC); > > Don't you need port lock here? What if the IRQ handler gets executed in a different > CPU? - Thank you for reviewing. Since we are using a single IRQ line, the IRQ line remains in a disabled (masked) state until the interrupts are handled. Therefore, there is no need for a locking mechanism in this case. > > + val &= ~pcie_read(pcie, AMD_MDB_TLP_IR_MASK_MISC); > > + for_each_set_bit(i, &val, 32) > > + generic_handle_domain_irq(pcie->mdb_domain, i); > > + pcie_write(pcie, val, AMD_MDB_TLP_IR_STATUS_MISC); > > Clear the IRQs before handling them. - Thank you for reviewing, This interrupt handling patch is authored by Marc zingier. This is intentionally done this way so that IRQ's are masked before they are handled. > > > + > > + return IRQ_HANDLED; > > +} > > + > > +#define _IC(x, s)[AMD_MDB_PCIE_INTR_ ## x] = { __stringify(x), s } > > + > > +static const struct { > > + const char *sym; > > + const char *str; > > +} intr_cause[32] = { > > + _IC(CMPL_TIMEOUT, "completion timeout"), > > + _IC(PM_PME_RCVD, "PM_PME message received"), > > + _IC(PME_TO_ACK_RCVD, "PME_TO_ACK message received"), > > + _IC(MISC_CORRECTABLE, "Correctable error message"), > > + _IC(NONFATAL, "Non fatal error message"), > > + _IC(FATAL, "Fatal error message"), > > +}; > > + > > +static void amd_mdb_mask_event_irq(struct irq_data *d) { > > + struct amd_mdb_pcie *pcie = irq_data_get_irq_chip_data(d); > > + struct dw_pcie *pci = &pcie->pci; > > + struct dw_pcie_rp *port = &pci->pp; > > + u32 val; > > + > > + raw_spin_lock(&port->lock); > > Why this lock is non-irq variant compared to amd_mdb_mask_intx_irq()? > > > + val = pcie_read(pcie, AMD_MDB_TLP_IR_STATUS_MISC); - Here I need to mask the interrupts before handling. Refer https://gitenterprise.xilinx.com/Linux/linux-xlnx/blob/xlnx_rebase_v6.1-next/drivers/pci/controller/pcie-xilinx-cpm.c#L255 > > + val &= ~BIT(d->hwirq); > > + pcie_write(pcie, val, AMD_MDB_TLP_IR_STATUS_MISC); > > + raw_spin_unlock(&port->lock); > > +} > > + > > +static void amd_mdb_unmask_event_irq(struct irq_data *d) { > > + struct amd_mdb_pcie *pcie = irq_data_get_irq_chip_data(d); > > + struct dw_pcie *pci = &pcie->pci; > > + struct dw_pcie_rp *port = &pci->pp; > > + u32 val; > > + > > + raw_spin_lock(&port->lock); > > Same here. > > > + val = pcie_read(pcie, AMD_MDB_TLP_IR_STATUS_MISC); > > + val |= BIT(d->hwirq); > > + pcie_write(pcie, val, AMD_MDB_TLP_IR_STATUS_MISC); > > + raw_spin_unlock(&port->lock); > > +} > > + > > +static struct irq_chip amd_mdb_event_irq_chip = { > > + .name = "RC-Event", > > Add the 'AMD MDB' prefix. - Thank you for reviewing, will add this in next patch. > > > + .irq_mask = amd_mdb_mask_event_irq, > > + .irq_unmask = amd_mdb_unmask_event_irq, > > +}; > > + > > +static int amd_mdb_pcie_event_map(struct irq_domain *domain, > > + unsigned int irq, irq_hw_number_t hwirq) { > > + irq_set_chip_and_handler(irq, &amd_mdb_event_irq_chip, > > + handle_level_irq); > > + irq_set_chip_data(irq, domain->host_data); > > + irq_set_status_flags(irq, IRQ_LEVEL); > > newline here. - Thank you for reviewing, will update this in next patch. > > > + return 0; > > +} > > + > > +static const struct irq_domain_ops event_domain_ops = { > > + .map = amd_mdb_pcie_event_map, > > +}; > > + > > +static void amd_mdb_pcie_free_irq_domains(struct amd_mdb_pcie *pcie) > > +{ > > + if (pcie->intx_domain) { > > + irq_domain_remove(pcie->intx_domain); > > + pcie->intx_domain = NULL; > > + } > > + > > + if (pcie->mdb_domain) { > > + irq_domain_remove(pcie->mdb_domain); > > + pcie->mdb_domain = NULL; > > + } > > +} > > + > > +/** > > + * amd_mdb_pcie_init_irq_domains - Initialize IRQ domain > > + * @pcie: PCIe port information > > + * @pdev: platform device > > + * Return: '0' on success and error value on failure */ static int > > +amd_mdb_pcie_init_irq_domains(struct amd_mdb_pcie *pcie, > > + struct platform_device *pdev) > > +{ > > + struct dw_pcie *pci = &pcie->pci; > > + struct dw_pcie_rp *pp = &pci->pp; > > + struct device *dev = &pdev->dev; > > + struct device_node *node = dev->of_node; > > + struct device_node *pcie_intc_node; > > + > > + /* Setup INTx */ > > + pcie_intc_node = of_get_next_child(node, NULL); > > + if (!pcie_intc_node) { > > + dev_err(dev, "No PCIe Intc node found\n"); > > + return -EINVAL; > > -ENODATA > > > + } > > + > > + pcie->mdb_domain = irq_domain_add_linear(pcie_intc_node, 32, > > + &event_domain_ops, pcie); > > + if (!pcie->mdb_domain) > > + goto out; > > + > > + irq_domain_update_bus_token(pcie->mdb_domain, > DOMAIN_BUS_NEXUS); > > + > > + pcie->intx_domain = irq_domain_add_linear(pcie_intc_node, > PCI_NUM_INTX, > > + &amd_intx_domain_ops, pcie); > > + if (!pcie->intx_domain) > > + goto mdb_out; > > + > > + irq_domain_update_bus_token(pcie->intx_domain, > DOMAIN_BUS_WIRED); > > + > > + of_node_put(pcie_intc_node); > > Move this before irq_domain_update_bus_token(). > > > + raw_spin_lock_init(&pp->lock); > > + > > + return 0; > > +mdb_out: > > + amd_mdb_pcie_free_irq_domains(pcie); > > +out: > > + of_node_put(pcie_intc_node); > > + dev_err(dev, "Failed to allocate IRQ domains\n"); > > It is not a good practice to print error logs and return a fixed error no in goto labels. If > one more condition gets added to this function later, these all should be moved to > the respective error check. So please do so now itself even if it adds a bit of > redundancy. > > The error log could be improved by stating which domain failed. Thank you for reviewing, Will update this in next patch. > > > + > > + return -ENOMEM; > > +} > > + > > +static irqreturn_t amd_mdb_pcie_intr_handler(int irq, void *args) { > > + struct amd_mdb_pcie *pcie = args; > > + struct device *dev; > > + struct irq_data *d; > > + > > + dev = pcie->pci.dev; > > + > > + d = irq_domain_get_irq_data(pcie->mdb_domain, irq); > > + if (intr_cause[d->hwirq].str) > > + dev_warn(dev, "%s\n", intr_cause[d->hwirq].str); > > Move this to dev_dbg(). - Thank you for the feedback. This message is intended as a warning for the end user to indicate that an event has occurred, and not just for debugging purposes. Hence, we believe dev_warn() is the appropriate log level for this scenario. Please let us know if you have further concerns. > > + else > > + dev_warn(dev, "Unknown IRQ %ld\n", d->hwirq); > > dev_WARN_ONCE() to avoid spamming the log. - Thank you reviewing, I ll change it in next patch. > > > + > > + return IRQ_HANDLED; > > +} > > + > > +static int amd_mdb_setup_irq(struct amd_mdb_pcie *pcie, > > + struct platform_device *pdev) { > > + struct dw_pcie *pci = &pcie->pci; > > + struct dw_pcie_rp *pp = &pci->pp; > > + struct device *dev = &pdev->dev; > > + int i, irq, err; > > + > > + pp->irq = platform_get_irq(pdev, 0); > > + if (pp->irq < 0) > > + return pp->irq; > > + > > + for (i = 0; i < ARRAY_SIZE(intr_cause); i++) { > > + if (!intr_cause[i].str) > > + continue; > > + irq = irq_create_mapping(pcie->mdb_domain, i); > > + if (!irq) { > > + dev_err(dev, "Failed to map mdb domain interrupt\n"); > > + return -ENXIO; > > -ENOMEM > > > + } > > + err = devm_request_irq(dev, irq, amd_mdb_pcie_intr_handler, > > + IRQF_SHARED | IRQF_NO_THREAD, > > + intr_cause[i].sym, pcie); > > IRQ name should have the 'amd_mdb' prefix and also the domain number to > uniquely identify the interrupt belonging to each host bridge. - Thank you for the feedback. We will update the IRQ name to include the amd_mdb prefix in the next patch. However, including the domain number may not be necessary in this case since both controllers are not expected to be present simultaneously. > > + if (err) { > > + dev_err(dev, "Failed to request IRQ %d\n", irq); > > + return err; > > + } > > + } > > + > > + /* Plug the main event chained handler */ > > + err = devm_request_irq(dev, pp->irq, amd_mdb_pcie_event_flow, > > + IRQF_SHARED | IRQF_NO_THREAD, "pcie_irq", pcie); > > Same as above. - Thank you for feedback, will update in next patch. > > > + if (err) { > > + dev_err(dev, "Failed to request event IRQ %d\n", pp->irq); > > + return err; > > + } > > + > > + return 0; > > +} > > + > > +static int amd_mdb_add_pcie_port(struct amd_mdb_pcie *pcie, > > + struct platform_device *pdev) > > +{ > > + struct dw_pcie *pci = &pcie->pci; > > + struct dw_pcie_rp *pp = &pci->pp; > > + struct device *dev = &pdev->dev; > > + int ret; > > + > > + pcie->slcr = devm_platform_ioremap_resource_byname(pdev, "slcr"); > > + if (IS_ERR(pcie->slcr)) > > + return PTR_ERR(pcie->slcr); > > + > > + ret = amd_mdb_pcie_init_irq_domains(pcie, pdev); > > + if (ret) > > + return ret; > > + > > + amd_mdb_pcie_init_port(pcie); > > + > > + ret = amd_mdb_setup_irq(pcie, pdev); > > + if (ret) { > > + dev_err(dev, "Failed to set up interrupts\n"); > > + goto out; > > + } > > + > > + pp->ops = &amd_mdb_pcie_host_ops; > > + > > + ret = dw_pcie_host_init(pp); > > + if (ret) { > > + dev_err(dev, "Failed to initialize host\n"); > > + goto out; > > + } > > + > > + return 0; > > + > > +out: > > + amd_mdb_pcie_free_irq_domains(pcie); > > + return ret; > > +} > > + > > +static int amd_mdb_pcie_probe(struct platform_device *pdev) { > > + struct device *dev = &pdev->dev; > > + struct amd_mdb_pcie *pcie; > > + struct dw_pcie *pci; > > + > > + pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL); > > + if (!pcie) > > + return -ENOMEM; > > + > > + pci = &pcie->pci; > > + pci->dev = dev; > > + > > + platform_set_drvdata(pdev, pcie); > > + > > + return amd_mdb_add_pcie_port(pcie, pdev); } > > + > > +static const struct of_device_id amd_mdb_pcie_of_match[] = { > > + { > > + .compatible = "amd,versal2-mdb-host", > > + }, > > + {}, > > +}; > > + > > +static struct platform_driver amd_mdb_pcie_driver = { > > + .driver = { > > + .name = "amd-mdb-pcie", > > + .of_match_table = amd_mdb_pcie_of_match, > > + .suppress_bind_attrs = true, > > Consider using PROBE_PREFER_ASYNCHRONOUS to speed up the probe. - Thank you for the suggestion. However, in future probe function involves handling the PCIe PERST# signal, which may require synchronous execution to ensure proper initialization of the device and its dependencies. > > - Mani > > -- > மணிவண்ணன் சதாசிவம்