Commit 5f0c2ee1 authored by Loic Poulain's avatar Loic Poulain Committed by Greg Kroah-Hartman
Browse files

bus: mhi: pci-generic: Fix hibernation 

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.

Link: https://lore.kernel.org/r/1622571445-4505-1-git-send-email-loic.poulain@linaro.org


Reported-by: default avatarShujun Wang <wsj20369@163.com>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: default avatarLoic Poulain <loic.poulain@linaro.org>
Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20210606153741.20725-4-manivannan.sadhasivam@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0b67808a

drivers/bus/mhi/pci_generic.c

+35 −1
Original line number Diff line number Diff line
@@ -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 = {