diff mbox series

[v8,07/10] mhi: pci_generic: Add health-check

Message ID 1609776899-30664-8-git-send-email-loic.poulain@linaro.org
State Accepted
Commit 8562d4fe34a3ef52da077f77985994bb9ad1f83e
Headers show
Series mhi: pci_generic: Misc improvements | expand

Commit Message

Loic Poulain Jan. 4, 2021, 4:14 p.m. UTC 
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>

---
 drivers/bus/mhi/pci_generic.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

-- 
2.7.4

Comments

Kalle Valo Jan. 28, 2021, 5:55 a.m. UTC | #1 
Loic Poulain <loic.poulain@linaro.org> writes:

> 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>


[...]

> +#define HEALTH_CHECK_PERIOD (HZ * 2)


[...]

> +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);

> +}


Sorry for the late reply, I see that this is already applied. But I
wonder how this 2s polling affects battery life? Especially I'm worried
about increased power consumption with ath11k on laptops.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Kalle Valo Jan. 28, 2021, 5:59 a.m. UTC | #2 
Kalle Valo <kvalo@codeaurora.org> writes:

> Loic Poulain <loic.poulain@linaro.org> writes:

>

>> 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>

>

> [...]

>

>> +#define HEALTH_CHECK_PERIOD (HZ * 2)

>

> [...]

>

>> +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);

>> +}

>

> Sorry for the late reply, I see that this is already applied. But I

> wonder how this 2s polling affects battery life? Especially I'm worried

> about increased power consumption with ath11k on laptops.


Nevermind, I didn't realise that this is for pci_generic and ath11k does
not use it. Sorry for the noise.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
diff mbox series

Patch

diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
index 2cc4410..3eac410 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 @@  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: