diff mbox series

[v4,06/10] mhi: pci_generic: Add suspend/resume/recovery procedure

Message ID 1607594575-31590-7-git-send-email-loic.poulain@linaro.org
State Superseded
Headers show
Series mhi: pci_generic: Misc improvements | expand

Commit Message

Loic Poulain Dec. 10, 2020, 10:02 a.m. UTC
Add support for system wide suspend/resume. During suspend, MHI
device controller must be put in M3 state and PCI bus in D3 state.

Add a recovery procedure allowing to reinitialize the device in case
of error during resume steps, which can happen if device loses power
(and so its context) while system suspend.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

---
 drivers/bus/mhi/pci_generic.c | 102 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)

-- 
2.7.4

Comments

Hemant Kumar Dec. 11, 2020, 8:22 p.m. UTC | #1
Hi Loic,

On 12/10/20 2:02 AM, Loic Poulain wrote:
> Add support for system wide suspend/resume. During suspend, MHI

> device controller must be put in M3 state and PCI bus in D3 state.

> 

> Add a recovery procedure allowing to reinitialize the device in case

> of error during resume steps, which can happen if device loses power

> (and so its context) while system suspend.

> 

> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

> ---

>[..]

> +int  __maybe_unused mhi_pci_suspend(struct device *dev)

suspend API is not static but resume is. Any reason for that ?
> +{

> +	struct pci_dev *pdev = to_pci_dev(dev);

> +	struct mhi_pci_device *mhi_pdev = dev_get_drvdata(dev);

> +	struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;

> +

> +	cancel_work_sync(&mhi_pdev->recovery_work);

> +

> +	/* Transition to M3 state */

> +	mhi_pm_suspend(mhi_cntrl);

> +

> +	pci_save_state(pdev);

> +	pci_disable_device(pdev);

> +	pci_wake_from_d3(pdev, true);

> +	pci_set_power_state(pdev, PCI_D3hot);

> +

> +	return 0;

> +}

> +

> +static int __maybe_unused mhi_pci_resume(struct device *dev)

> +{

> +	struct pci_dev *pdev = to_pci_dev(dev);

> +	struct mhi_pci_device *mhi_pdev = dev_get_drvdata(dev);

> +	struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;

> +	int err;

> +

> +	pci_set_power_state(pdev, PCI_D0);

> +	pci_restore_state(pdev);

> +	pci_set_master(pdev);

> +

> +	err = pci_enable_device(pdev);

> +	if (err)

> +		goto err_recovery;

> +

> +	/* Exit M3, transition to M0 state */

> +	err = mhi_pm_resume(mhi_cntrl);

> +	if (err) {

> +		dev_err(&pdev->dev, "failed to resume device: %d\n", err);

> +		goto err_recovery;

> +	}

> +

> +	return 0;

> +

> +err_recovery:

> +	/* The device may have loose power or crashed, try recovering it */

> +	queue_work(system_long_wq, &mhi_pdev->recovery_work);

> +	return 0;

> +}

> +

> +static const struct dev_pm_ops mhi_pci_pm_ops = {

> +	SET_SYSTEM_SLEEP_PM_OPS(mhi_pci_suspend, mhi_pci_resume)

> +};

> +

>   static struct pci_driver mhi_pci_driver = {

>   	.name		= "mhi-pci-generic",

>   	.id_table	= mhi_pci_id_table,

>   	.probe		= mhi_pci_probe,

>   	.remove		= mhi_pci_remove,

>   	.err_handler	= &mhi_pci_err_handler,

> +	.driver.pm	= &mhi_pci_pm_ops

>   };

>   module_pci_driver(mhi_pci_driver);

>   

> 


Overall change looks good from my side. Once you address or answer my 
query you can add my

Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>


Thanks,
Hemant
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
Loic Poulain Dec. 14, 2020, 2:06 p.m. UTC | #2
On Fri, 11 Dec 2020 at 21:22, Hemant Kumar <hemantk@codeaurora.org> wrote:
>

> Hi Loic,

>

> On 12/10/20 2:02 AM, Loic Poulain wrote:

> > Add support for system wide suspend/resume. During suspend, MHI

> > device controller must be put in M3 state and PCI bus in D3 state.

> >

> > Add a recovery procedure allowing to reinitialize the device in case

> > of error during resume steps, which can happen if device loses power

> > (and so its context) while system suspend.

> >

> > Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

> > ---

> >[..]

> > +int  __maybe_unused mhi_pci_suspend(struct device *dev)

> suspend API is not static but resume is. Any reason for that ?


No, going to fix that, thanks.
diff mbox series

Patch

diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
index d70d3ea..0c16f36 100644
--- a/drivers/bus/mhi/pci_generic.c
+++ b/drivers/bus/mhi/pci_generic.c
@@ -13,6 +13,7 @@ 
 #include <linux/mhi.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/workqueue.h>
 
 #define MHI_PCI_DEFAULT_BAR_NUM 0
 
@@ -185,6 +186,7 @@  enum mhi_pci_device_status {
 struct mhi_pci_device {
 	struct mhi_controller mhi_cntrl;
 	struct pci_saved_state *pci_state;
+	struct work_struct recovery_work;
 	unsigned long status;
 };
 
@@ -312,6 +314,48 @@  static void mhi_pci_runtime_put(struct mhi_controller *mhi_cntrl)
 	/* no PM for now */
 }
 
+static void mhi_pci_recovery_work(struct work_struct *work)
+{
+	struct mhi_pci_device *mhi_pdev = container_of(work, struct mhi_pci_device,
+						       recovery_work);
+	struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
+	struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
+	int err;
+
+	dev_warn(&pdev->dev, "device recovery started\n");
+
+	/* Clean up MHI state */
+	if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
+		mhi_power_down(mhi_cntrl, false);
+		mhi_unprepare_after_power_down(mhi_cntrl);
+	}
+
+	/* Check if we can recover without full reset */
+	pci_set_power_state(pdev, PCI_D0);
+	pci_load_saved_state(pdev, mhi_pdev->pci_state);
+	pci_restore_state(pdev);
+
+	if (!mhi_pci_is_alive(mhi_cntrl))
+		goto err_try_reset;
+
+	err = mhi_prepare_for_power_up(mhi_cntrl);
+	if (err)
+		goto err_try_reset;
+
+	err = mhi_sync_power_up(mhi_cntrl);
+	if (err)
+		goto err_unprepare;
+
+	set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
+	return;
+
+err_unprepare:
+	mhi_unprepare_after_power_down(mhi_cntrl);
+err_try_reset:
+	if (pci_reset_function(pdev))
+		dev_err(&pdev->dev, "Recovery failed\n");
+}
+
 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;
@@ -326,6 +370,8 @@  static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (!mhi_pdev)
 		return -ENOMEM;
 
+	INIT_WORK(&mhi_pdev->recovery_work, mhi_pci_recovery_work);
+
 	mhi_cntrl_config = info->config;
 	mhi_cntrl = &mhi_pdev->mhi_cntrl;
 
@@ -390,6 +436,8 @@  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;
 
+	cancel_work_sync(&mhi_pdev->recovery_work);
+
 	if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
 		mhi_power_down(mhi_cntrl, true);
 		mhi_unprepare_after_power_down(mhi_cntrl);
@@ -455,12 +503,66 @@  static const struct pci_error_handlers mhi_pci_err_handler = {
 	.reset_done = mhi_pci_reset_done,
 };
 
+int  __maybe_unused mhi_pci_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct mhi_pci_device *mhi_pdev = dev_get_drvdata(dev);
+	struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
+
+	cancel_work_sync(&mhi_pdev->recovery_work);
+
+	/* Transition to M3 state */
+	mhi_pm_suspend(mhi_cntrl);
+
+	pci_save_state(pdev);
+	pci_disable_device(pdev);
+	pci_wake_from_d3(pdev, true);
+	pci_set_power_state(pdev, PCI_D3hot);
+
+	return 0;
+}
+
+static int __maybe_unused mhi_pci_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct mhi_pci_device *mhi_pdev = dev_get_drvdata(dev);
+	struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
+	int err;
+
+	pci_set_power_state(pdev, PCI_D0);
+	pci_restore_state(pdev);
+	pci_set_master(pdev);
+
+	err = pci_enable_device(pdev);
+	if (err)
+		goto err_recovery;
+
+	/* Exit M3, transition to M0 state */
+	err = mhi_pm_resume(mhi_cntrl);
+	if (err) {
+		dev_err(&pdev->dev, "failed to resume device: %d\n", err);
+		goto err_recovery;
+	}
+
+	return 0;
+
+err_recovery:
+	/* The device may have loose power or crashed, try recovering it */
+	queue_work(system_long_wq, &mhi_pdev->recovery_work);
+	return 0;
+}
+
+static const struct dev_pm_ops mhi_pci_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(mhi_pci_suspend, mhi_pci_resume)
+};
+
 static struct pci_driver mhi_pci_driver = {
 	.name		= "mhi-pci-generic",
 	.id_table	= mhi_pci_id_table,
 	.probe		= mhi_pci_probe,
 	.remove		= mhi_pci_remove,
 	.err_handler	= &mhi_pci_err_handler,
+	.driver.pm	= &mhi_pci_pm_ops
 };
 module_pci_driver(mhi_pci_driver);