This is a note to let you know that I've just added the patch titled
bus: mhi: pci-generic: Fix hibernation
to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 5f0c2ee1fe8de700dd0d1cdc63e1a7338e2d3a3d Mon Sep 17 00:00:00 2001
From: Loic Poulain loic.poulain@linaro.org Date: Sun, 6 Jun 2021 21:07:41 +0530 Subject: 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@lina... Reported-by: Shujun Wang wsj20369@163.com Cc: stable stable@vger.kernel.org Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Signed-off-by: Loic Poulain loic.poulain@linaro.org Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Link: https://lore.kernel.org/r/20210606153741.20725-4-manivannan.sadhasivam@linar... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 = {