leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

mhi: pci_generic: Add suspend/resume/recovery procedure

Browse Source 
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.

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

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
This commit is contained in:
Loic Poulain 2021-01-04 17:14:54 +01:00 committed by Manivannan Sadhasivam
parent 8ccc3279fc
commit 7389337f0a
1 changed files with 105 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

105
drivers/bus/mhi/pci_generic.c
View File

@ -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
@ -186,6 +187,7 @@ 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;
};
@ -313,6 +315,50 @@ 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;
dev_dbg(&pdev->dev, "Recovery completed\n");
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;
@ -328,6 +374,8 @@ 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;
@ -391,6 +439,8 @@ 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);
@ -456,12 +506,67 @@ static const struct pci_error_handlers mhi_pci_err_handler = {
.reset_done = mhi_pci_reset_done,
};
static 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 err;
}
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);