From: Brian Norris briannorris@google.com

As the comments in pci_pm_thaw_noirq() suggest, pci_restore_state() may need to restore MSI-X state in MMIO space. This is only possible if we reach D0; if we failed to power up, this might produce a fatal error when touching memory space.

Check for errors (as the "verify" in "pci_pm_power_up_and_verify_state" implies), and skip restoring if it fails.

This mitigates errors seen during resume_noirq, for example, when the platform did not resume the link properly.

Cc: stable@vger.kernel.org Signed-off-by: Brian Norris briannorris@google.com Signed-off-by: Brian Norris briannorris@chromium.org ---

drivers/pci/pci-driver.c | 12 +++++++++--- drivers/pci/pci.c | 13 +++++++++++-- drivers/pci/pci.h | 2 +- 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 302d61783f6c..d66d95bd0ca2 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -557,7 +557,13 @@ static void pci_pm_default_resume(struct pci_dev *pci_dev)

static void pci_pm_default_resume_early(struct pci_dev *pci_dev) { - pci_pm_power_up_and_verify_state(pci_dev); + /* + * If we failed to reach D0, we'd better not touch MSI-X state in MMIO + * space. + */ + if (pci_pm_power_up_and_verify_state(pci_dev)) + return; + pci_restore_state(pci_dev); pci_pme_restore(pci_dev); } @@ -1101,8 +1107,8 @@ static int pci_pm_thaw_noirq(struct device *dev) * in case the driver's "freeze" callbacks put it into a low-power * state. */ - pci_pm_power_up_and_verify_state(pci_dev); - pci_restore_state(pci_dev); + if (!pci_pm_power_up_and_verify_state(pci_dev)) + pci_restore_state(pci_dev);

if (pci_has_legacy_pm_support(pci_dev)) return 0; diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e698278229f2..c75fec3b094f 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3144,10 +3144,19 @@ void pci_d3cold_disable(struct pci_dev *dev) } EXPORT_SYMBOL_GPL(pci_d3cold_disable);

-void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev) +int pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev) { - pci_power_up(pci_dev); + int ret; + + ret = pci_power_up(pci_dev); pci_update_current_state(pci_dev, PCI_D0); + + if (ret < 0 && pci_dev->current_state == PCI_D3cold) { + dev_err(&pci_dev->dev, "Failed to power up device: %d\n", ret); + return ret; + } + + return 0; }

/** diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 1c48bc447f58..87ad201417d5 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -233,7 +233,7 @@ void pci_dev_adjust_pme(struct pci_dev *dev); void pci_dev_complete_resume(struct pci_dev *pci_dev); void pci_config_pm_runtime_get(struct pci_dev *dev); void pci_config_pm_runtime_put(struct pci_dev *dev); -void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev); +int pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev); void pci_pm_init(struct pci_dev *dev); void pci_ea_init(struct pci_dev *dev); void pci_msi_init(struct pci_dev *dev);