@@ -14,12 +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 DEV_RESET_REG (0xB0)
+#define HEALTH_CHECK_PERIOD (HZ * 5)
+
/**
* struct mhi_pci_dev_info - MHI PCI device specific information
* @config: MHI controller configuration
@@ -190,6 +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;
};
@@ -332,6 +336,8 @@ 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);
@@ -355,6 +361,7 @@ static void mhi_pci_recovery_work(struct work_struct *work)
goto err_unprepare;
set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
+ mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
return;
err_unprepare:
@@ -364,6 +371,21 @@ 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;
@@ -379,6 +401,7 @@ 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;
@@ -429,6 +452,9 @@ 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:
@@ -444,6 +470,7 @@ 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)) {
@@ -464,6 +491,8 @@ 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);
@@ -507,6 +536,7 @@ 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,
@@ -567,6 +597,7 @@ 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 */
@@ -602,6 +633,9 @@ 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:
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> --- drivers/bus/mhi/pci_generic.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) -- 2.7.4