diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4d7c9f64ea24..eb0c55078d5e 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4718,6 +4718,11 @@ static int pcie_wait_for_link_status(struct pci_dev *pdev, * @pdev: Device whose link to retrain. * @use_lt: Use the LT bit if TRUE, or the DLLLA bit if FALSE, for status. * + * Trigger retraining of the PCIe Link and wait for the completion of the + * retraining. As link retraining is known to asserts LBMS and may change + * the Link Speed, LBMS is cleared after the retraining and the Link Speed + * of the subordinate bus is updated. + * * Retrain completion status is retrieved from the Link Status Register * according to @use_lt. It is not verified whether the use of the DLLLA * bit is valid. @@ -4757,7 +4762,19 @@ int pcie_retrain_link(struct pci_dev *pdev, bool use_lt) * to track link speed or width changes made by hardware itself * in attempt to correct unreliable link operation. */ - pcie_reset_lbms_count(pdev); + pcie_reset_lbms(pdev); + + /* + * Ensure the Link Speed updates after retraining in case the Link + * Speed was changed because of the retraining. While the bwctrl's + * IRQ handler normally picks up the new Link Speed, clearing LBMS + * races with the IRQ handler reading the Link Status register and + * can result in the handler returning early without updating the + * Link Speed. + */ + if (pdev->subordinate) + pcie_update_link_speed(pdev->subordinate); + return rc; } |