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Message-ID: <253f689e-ce60-ee87-6ec9-9efc9b001960@linux.intel.com>
Date: Sun, 8 Jan 2023 19:44:08 +0530
From: "Kumar, M Chetan" <m.chetan.kumar@...ux.intel.com>
To: Jesse Brandeburg <jesse.brandeburg@...el.com>,
netdev@...r.kernel.org
Cc: kuba@...nel.org, davem@...emloft.net, johannes@...solutions.net,
ryazanov.s.a@...il.com, loic.poulain@...aro.org,
ilpo.jarvinen@...ux.intel.com, ricardo.martinez@...ux.intel.com,
chiranjeevi.rapolu@...ux.intel.com, haijun.liu@...iatek.com,
edumazet@...gle.com, pabeni@...hat.com, linuxwwan@...el.com,
linuxwwan_5g@...el.com, chandrashekar.devegowda@...el.com,
matthias.bgg@...il.com, linux-arm-kernel@...ts.infradead.org,
linux-mediatek@...ts.infradead.org,
Madhusmita Sahu <madhusmita.sahu@...el.com>
Subject: Re: [PATCH v3 net-next 3/5] net: wwan: t7xx: PCIe reset rescan
On 1/7/2023 12:12 AM, Jesse Brandeburg wrote:
> On 1/6/2023 8:27 AM, m.chetan.kumar@...ux.intel.com wrote:
>> From: M Chetan Kumar <m.chetan.kumar@...ux.intel.com>
>>
>> PCI rescan module implements "rescan work queue".
>> In firmware flashing or coredump collection procedure
>> WWAN device is programmed to boot in fastboot mode and
>> a work item is scheduled for removal & detection.
>>
>> The WWAN device is reset using APCI call as part driver
>> removal flow. Work queue rescans pci bus at fixed interval
>> for device detection, later when device is detect work queue
>> exits.
>>
>> Signed-off-by: Haijun Liu <haijun.liu@...iatek.com>
>> Co-developed-by: Madhusmita Sahu <madhusmita.sahu@...el.com>
>> Signed-off-by: Madhusmita Sahu <madhusmita.sahu@...el.com>
>> Signed-off-by: Ricardo Martinez <ricardo.martinez@...ux.intel.com>
>> Signed-off-by: M Chetan Kumar <m.chetan.kumar@...ux.intel.com>
>> Signed-off-by: Devegowda Chandrashekar
>> <chandrashekar.devegowda@...el.com>
>> --
>> v3:
>> * No Change.
>> v2:
>> * Drop empty line inside critical sections.
>> * Correct log message.
>> * Correct logic inside t7xx_always_match().
>> * Drop hp_enable changes.
>> * Drop g_ prefix from t7xx_rescan_ctx.
>> * Use tab before comment in struct decl.
>> * Remove extra white space.
>> * Drop modem exception state check.
>> * Crit section newlines.
>> * Remove unnecessary header files inclusion.
>> * Drop spinlock around reset and rescan flow.
>> ---
>> drivers/net/wwan/t7xx/Makefile | 3 +-
>> drivers/net/wwan/t7xx/t7xx_modem_ops.c | 3 +
>> drivers/net/wwan/t7xx/t7xx_pci.c | 56 ++++++++++++++-
>> drivers/net/wwan/t7xx/t7xx_pci_rescan.c | 96 +++++++++++++++++++++++++
>> drivers/net/wwan/t7xx/t7xx_pci_rescan.h | 28 ++++++++
>> 5 files changed, 184 insertions(+), 2 deletions(-)
>> create mode 100644 drivers/net/wwan/t7xx/t7xx_pci_rescan.c
>> create mode 100644 drivers/net/wwan/t7xx/t7xx_pci_rescan.h
>>
>> diff --git a/drivers/net/wwan/t7xx/Makefile
>> b/drivers/net/wwan/t7xx/Makefile
>> index 268ff9e87e5b..ba5c607404a4 100644
>> --- a/drivers/net/wwan/t7xx/Makefile
>> +++ b/drivers/net/wwan/t7xx/Makefile
>> @@ -17,7 +17,8 @@ mtk_t7xx-y:= t7xx_pci.o \
>> t7xx_hif_dpmaif_tx.o \
>> t7xx_hif_dpmaif_rx.o \
>> t7xx_dpmaif.o \
>> - t7xx_netdev.o
>> + t7xx_netdev.o \
>> + t7xx_pci_rescan.o
>> mtk_t7xx-$(CONFIG_WWAN_DEBUGFS) += \
>> t7xx_port_trace.o \
>> diff --git a/drivers/net/wwan/t7xx/t7xx_modem_ops.c
>> b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
>> index cbd65aa48721..2fcaea4694ba 100644
>> --- a/drivers/net/wwan/t7xx/t7xx_modem_ops.c
>> +++ b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
>> @@ -37,6 +37,7 @@
>> #include "t7xx_modem_ops.h"
>> #include "t7xx_netdev.h"
>> #include "t7xx_pci.h"
>> +#include "t7xx_pci_rescan.h"
>> #include "t7xx_pcie_mac.h"
>> #include "t7xx_port.h"
>> #include "t7xx_port_proxy.h"
>> @@ -194,6 +195,8 @@ static irqreturn_t t7xx_rgu_isr_thread(int irq,
>> void *data)
>> msleep(RGU_RESET_DELAY_MS);
>> t7xx_reset_device_via_pmic(t7xx_dev);
>> + t7xx_rescan_queue_work(t7xx_dev->pdev);
>> +
>> return IRQ_HANDLED;
>> }
>> diff --git a/drivers/net/wwan/t7xx/t7xx_pci.c
>> b/drivers/net/wwan/t7xx/t7xx_pci.c
>> index 871f2a27a398..1e953ec7dd00 100644
>> --- a/drivers/net/wwan/t7xx/t7xx_pci.c
>> +++ b/drivers/net/wwan/t7xx/t7xx_pci.c
>> @@ -38,6 +38,7 @@
>> #include "t7xx_mhccif.h"
>> #include "t7xx_modem_ops.h"
>> #include "t7xx_pci.h"
>> +#include "t7xx_pci_rescan.h"
>> #include "t7xx_pcie_mac.h"
>> #include "t7xx_reg.h"
>> #include "t7xx_state_monitor.h"
>> @@ -715,6 +716,7 @@ static int t7xx_pci_probe(struct pci_dev *pdev,
>> const struct pci_device_id *id)
>> return ret;
>> }
>> + t7xx_rescan_done();
>> t7xx_pcie_mac_set_int(t7xx_dev, MHCCIF_INT);
>> t7xx_pcie_mac_interrupts_en(t7xx_dev);
>> @@ -754,7 +756,59 @@ static struct pci_driver t7xx_pci_driver = {
>> .shutdown = t7xx_pci_shutdown,
>> };
>> -module_pci_driver(t7xx_pci_driver);
>> +static int __init t7xx_pci_init(void)
>> +{
>> + int ret;
>> +
>> + t7xx_pci_dev_rescan();
>> + ret = t7xx_rescan_init();
>> + if (ret) {
>> + pr_err("Failed to init t7xx rescan work\n");
>> + return ret;
>> + }
>> +
>> + return pci_register_driver(&t7xx_pci_driver);
>> +}
>> +module_init(t7xx_pci_init);
>> +
>> +static int t7xx_always_match(struct device *dev, const void *data)
>> +{
>> + struct pci_dev *pdev = to_pci_dev(dev);
>> + const struct pci_device_id *id = data;
>> +
>> + if (pci_match_id(id, pdev))
>> + return 1;
>> +
>> + return 0;
>> +}
>> +
>> +static void __exit t7xx_pci_cleanup(void)
>> +{
>> + int remove_flag = 0;
>> + struct device *dev;
>> +
>> + dev = driver_find_device(&t7xx_pci_driver.driver, NULL,
>> &t7xx_pci_table[0],
>> + t7xx_always_match);
>> + if (dev) {
>> + pr_debug("unregister t7xx PCIe driver while device is still
>> exist.\n");
>
> nit: s/is still exist/still exists/
Ok, will correct it.
>
>> + put_device(dev);
>> + remove_flag = 1;
>> + } else {
>> + pr_debug("no t7xx PCIe driver found.\n");
>> + }
>> +
>> + pci_lock_rescan_remove();
>> + pci_unregister_driver(&t7xx_pci_driver);
>> + pci_unlock_rescan_remove();
>> +
>> + t7xx_rescan_deinit();
>> + if (remove_flag) {
>> + pr_debug("remove t7xx PCI device\n");
>> + pci_stop_and_remove_bus_device_locked(to_pci_dev(dev));
>> + }
>> +}
>> +
>> +module_exit(t7xx_pci_cleanup);
>> MODULE_AUTHOR("MediaTek Inc");
>> MODULE_DESCRIPTION("MediaTek PCIe 5G WWAN modem T7xx driver");
>> diff --git a/drivers/net/wwan/t7xx/t7xx_pci_rescan.c
>> b/drivers/net/wwan/t7xx/t7xx_pci_rescan.c
>> new file mode 100644
>> index 000000000000..67f13c035846
>> --- /dev/null
>> +++ b/drivers/net/wwan/t7xx/t7xx_pci_rescan.c
>> @@ -0,0 +1,96 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2021, MediaTek Inc.
>> + * Copyright (c) 2021-2023, Intel Corporation.
>> + */
>> +
>> +#define pr_fmt(fmt) KBUILD_MODNAME ":t7xx:%s: " fmt, __func__
>> +#define dev_fmt(fmt) "t7xx: " fmt
>> +
>> +#include <linux/delay.h>
>> +#include <linux/pci.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/workqueue.h>
>> +
>> +#include "t7xx_pci.h"
>> +#include "t7xx_pci_rescan.h"
>> +
>> +static struct remove_rescan_context t7xx_rescan_ctx;
>> +
>> +void t7xx_pci_dev_rescan(void)
>> +{
>> + struct pci_bus *b = NULL;
>> +
>> + pci_lock_rescan_remove();
>> + while ((b = pci_find_next_bus(b)))
>> + pci_rescan_bus(b);
>> + pci_unlock_rescan_remove();
>> +}
>> +
>> +void t7xx_rescan_done(void)
>> +{
>> + if (!atomic_read(&t7xx_rescan_ctx.rescan_done)) {
>> + atomic_set(&t7xx_rescan_ctx.rescan_done, 1);
>> + pr_debug("Rescan probe\n");
>> + } else {
>> + pr_debug("Init probe\n");
>> + }
>> +}
>> +
>> +static void t7xx_remove_rescan(struct work_struct *work)
>> +{
>> + int num_retries = RESCAN_RETRIES;
>> + struct pci_dev *pdev;
>> +
>> + atomic_set(&t7xx_rescan_ctx.rescan_done, 0);
>> + pdev = t7xx_rescan_ctx.dev;
>> +
>> + if (pdev) {
>> + pci_stop_and_remove_bus_device_locked(pdev);
>> + pr_debug("start remove and rescan flow\n");
>> + }
>> +
>> + do {
>> + t7xx_pci_dev_rescan();
>> +
>> + if (atomic_read(&t7xx_rescan_ctx.rescan_done))
>> + break;
>> +
>> + msleep(DELAY_RESCAN_MTIME);
>> + } while (num_retries--);
>> +}
>> +
>> +void t7xx_rescan_queue_work(struct pci_dev *pdev)
>> +{
>> + if (!atomic_read(&t7xx_rescan_ctx.rescan_done)) {
>> + dev_err(&pdev->dev, "Rescan failed\n");
>> + return;
>> + }
>> +
>> + t7xx_rescan_ctx.dev = pdev;
>> + queue_work(t7xx_rescan_ctx.pcie_rescan_wq,
>> &t7xx_rescan_ctx.service_task);
>> +}
>> +
>> +int t7xx_rescan_init(void)
>> +{
>> + atomic_set(&t7xx_rescan_ctx.rescan_done, 1);
>> + t7xx_rescan_ctx.dev = NULL;
>> +
>> + t7xx_rescan_ctx.pcie_rescan_wq =
>> create_singlethread_workqueue(MTK_RESCAN_WQ);
>> + if (!t7xx_rescan_ctx.pcie_rescan_wq) {
>> + pr_err("Failed to create workqueue: %s\n", MTK_RESCAN_WQ);
>> + return -ENOMEM;
>> + }
>> +
>> + INIT_WORK(&t7xx_rescan_ctx.service_task, t7xx_remove_rescan);
>> +
>> + return 0;
>> +}
>> +
>> +void t7xx_rescan_deinit(void)
>> +{
>> + t7xx_rescan_ctx.dev = NULL;
>> + atomic_set(&t7xx_rescan_ctx.rescan_done, 0);
>> + cancel_work_sync(&t7xx_rescan_ctx.service_task);
>> + destroy_workqueue(t7xx_rescan_ctx.pcie_rescan_wq);
>> +}
>> diff --git a/drivers/net/wwan/t7xx/t7xx_pci_rescan.h
>> b/drivers/net/wwan/t7xx/t7xx_pci_rescan.h
>> new file mode 100644
>> index 000000000000..80b25c44151c
>> --- /dev/null
>> +++ b/drivers/net/wwan/t7xx/t7xx_pci_rescan.h
>> @@ -0,0 +1,28 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only
>> + *
>> + * Copyright (c) 2021, MediaTek Inc.
>> + * Copyright (c) 2021-2023, Intel Corporation.
>> + */
>> +
>> +#ifndef __T7XX_PCI_RESCAN_H__
>> +#define __T7XX_PCI_RESCAN_H__
>> +
>> +#define MTK_RESCAN_WQ "mtk_rescan_wq"
>> +
>> +#define DELAY_RESCAN_MTIME 1000
>> +#define RESCAN_RETRIES 35
>> +
>> +struct remove_rescan_context {
>> + struct work_struct service_task;
>> + struct workqueue_struct *pcie_rescan_wq;
>> + struct pci_dev *dev;
>> + atomic_t rescan_done;
>> +};
>> +
>> +void t7xx_pci_dev_rescan(void);
>> +void t7xx_rescan_queue_work(struct pci_dev *pdev);
>> +int t7xx_rescan_init(void);
>> +void t7xx_rescan_deinit(void);
>> +void t7xx_rescan_done(void);
>> +
>> +#endif /* __T7XX_PCI_RESCAN_H__ */
>
--
Chetan
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