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mhi: pci_generic: Add health-check

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If the modem crashes for any reason, we may not be able to detect
it at MHI level (MHI registers not reachable anymore).

This patch implements a health-check mechanism to check regularly
that device is alive (MHI layer can communicate with). If device
is not alive (because a crash or unexpected reset), the recovery
procedure is triggered.

Tested successfully with Telit FN980m module.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
This commit is contained in:
Loic Poulain 2021-01-04 17:14:56 +01:00 committed by Manivannan Sadhasivam
parent b012ee6bfe
commit 8562d4fe34
1 changed files with 35 additions and 0 deletions
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35
drivers/bus/mhi/pci_generic.c
View file

@ -14,11 +14,15 @@
#include <linux/mhi.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#define MHI_PCI_DEFAULT_BAR_NUM 0
#define MHI_POST_RESET_DELAY_MS 500
#define HEALTH_CHECK_PERIOD (HZ * 2)
/**
* struct mhi_pci_dev_info - MHI PCI device specific information
* @config: MHI controller configuration
@ -189,6 +193,7 @@ struct mhi_pci_device {
struct mhi_controller mhi_cntrl;
struct pci_saved_state *pci_state;
struct work_struct recovery_work;
struct timer_list health_check_timer;
unsigned long status;
};
@ -326,6 +331,8 @@ static void mhi_pci_recovery_work(struct work_struct *work)
dev_warn(&pdev->dev, "device recovery started\n");
del_timer(&mhi_pdev->health_check_timer);
/* Clean up MHI state */
if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
mhi_power_down(mhi_cntrl, false);
@ -351,6 +358,7 @@ static void mhi_pci_recovery_work(struct work_struct *work)
dev_dbg(&pdev->dev, "Recovery completed\n");
set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
return;
err_unprepare:
@ -360,6 +368,21 @@ static void mhi_pci_recovery_work(struct work_struct *work)
dev_err(&pdev->dev, "Recovery failed\n");
}
static void health_check(struct timer_list *t)
{
struct mhi_pci_device *mhi_pdev = from_timer(mhi_pdev, t, health_check_timer);
struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
if (!mhi_pci_is_alive(mhi_cntrl)) {
dev_err(mhi_cntrl->cntrl_dev, "Device died\n");
queue_work(system_long_wq, &mhi_pdev->recovery_work);
return;
}
/* reschedule in two seconds */
mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
}
static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
const struct mhi_pci_dev_info *info = (struct mhi_pci_dev_info *) id->driver_data;
@ -376,6 +399,7 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return -ENOMEM;
INIT_WORK(&mhi_pdev->recovery_work, mhi_pci_recovery_work);
timer_setup(&mhi_pdev->health_check_timer, health_check, 0);
mhi_cntrl_config = info->config;
mhi_cntrl = &mhi_pdev->mhi_cntrl;
@ -427,6 +451,9 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
/* start health check */
mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
return 0;
err_unprepare:
@ -442,6 +469,7 @@ static void mhi_pci_remove(struct pci_dev *pdev)
struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
del_timer(&mhi_pdev->health_check_timer);
cancel_work_sync(&mhi_pdev->recovery_work);
if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
@ -459,6 +487,8 @@ static void mhi_pci_reset_prepare(struct pci_dev *pdev)
dev_info(&pdev->dev, "reset\n");
del_timer(&mhi_pdev->health_check_timer);
/* Clean up MHI state */
if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
mhi_power_down(mhi_cntrl, false);
@ -502,6 +532,7 @@ static void mhi_pci_reset_done(struct pci_dev *pdev)
}
set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
}
static pci_ers_result_t mhi_pci_error_detected(struct pci_dev *pdev,
@ -562,6 +593,7 @@ static int __maybe_unused mhi_pci_suspend(struct device *dev)
struct mhi_pci_device *mhi_pdev = dev_get_drvdata(dev);
struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
del_timer(&mhi_pdev->health_check_timer);
cancel_work_sync(&mhi_pdev->recovery_work);
/* Transition to M3 state */
@ -597,6 +629,9 @@ static int __maybe_unused mhi_pci_resume(struct device *dev)
goto err_recovery;
}
/* Resume health check */
mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
return 0;
err_recovery: