From: Loic Poulain <loic.poulain@xxxxxxxxxx> This patch fixes crash after resuming from hibernation. The issue occurs when mhi stack is builtin and so part of the 'restore-kernel', causing the device to be resumed from 'restored kernel' with a no more valid context (memory mappings etc...) and leading to spurious crashes. This patch fixes the issue by implementing proper freeze/restore callbacks. Reported-by: Shujun Wang <wsj20369@xxxxxxx> Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> Link: https://lore.kernel.org/r/1622571445-4505-1-git-send-email-loic.poulain@xxxxxxxxxx Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> --- drivers/bus/mhi/pci_generic.c | 36 ++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c index 0a6619ad292c..b3357a8a2fdb 100644 --- a/drivers/bus/mhi/pci_generic.c +++ b/drivers/bus/mhi/pci_generic.c @@ -935,9 +935,43 @@ static int __maybe_unused mhi_pci_resume(struct device *dev) return ret; } +static int __maybe_unused mhi_pci_freeze(struct device *dev) +{ + struct mhi_pci_device *mhi_pdev = dev_get_drvdata(dev); + struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl; + + /* We want to stop all operations, hibernation does not guarantee that + * device will be in the same state as before freezing, especially if + * the intermediate restore kernel reinitializes MHI device with new + * context. + */ + 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); + } + + return 0; +} + +static int __maybe_unused mhi_pci_restore(struct device *dev) +{ + struct mhi_pci_device *mhi_pdev = dev_get_drvdata(dev); + + /* Reinitialize the device */ + queue_work(system_long_wq, &mhi_pdev->recovery_work); + + return 0; +} + static const struct dev_pm_ops mhi_pci_pm_ops = { SET_RUNTIME_PM_OPS(mhi_pci_runtime_suspend, mhi_pci_runtime_resume, NULL) - SET_SYSTEM_SLEEP_PM_OPS(mhi_pci_suspend, mhi_pci_resume) +#ifdef CONFIG_PM_SLEEP + .suspend = mhi_pci_suspend, + .resume = mhi_pci_resume, + .freeze = mhi_pci_freeze, + .thaw = mhi_pci_restore, + .restore = mhi_pci_restore, +#endif }; static struct pci_driver mhi_pci_driver = { -- 2.25.1
