On Tue, Jun 01, 2021 at 08:17:25PM +0200, Loic Poulain wrote:
> 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>
Applied to mhi-fixes!
Thanks,
Mani
> ---
> 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 aa8f8d5..afa8763 100644
> --- a/drivers/bus/mhi/pci_generic.c
> +++ b/drivers/bus/mhi/pci_generic.c
> @@ -888,9 +888,43 @@ 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 = {
> --
> 2.7.4
>
