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authorLoic Poulain <loic.poulain@linaro.org>2021-01-04 19:14:56 +0300
committerManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>2021-01-04 19:20:25 +0300
commit8562d4fe34a3ef52da077f77985994bb9ad1f83e (patch)
tree5d7b0a107dd1e84892bc7a4028513912b5d1bab6 /drivers/bus
parentb012ee6bfe2ac99bdf7d70b7776187f416c1cab8 (diff)
downloadlinux-8562d4fe34a3ef52da077f77985994bb9ad1f83e.tar.xz
mhi: pci_generic: Add health-check
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>
Diffstat (limited to 'drivers/bus')
-rw-r--r--drivers/bus/mhi/pci_generic.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
index 2cc44100f0dc..3eac41072ad2 100644
--- a/drivers/bus/mhi/pci_generic.c
+++ b/drivers/bus/mhi/pci_generic.c
@@ -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 @@ err_try_reset:
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: