diff options
| -rw-r--r-- | drivers/pci/pci.c | 12 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 6 | ||||
| -rw-r--r-- | drivers/pci/quirks.c | 31 |
3 files changed, 35 insertions, 14 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 55d6124acb2d..7148a3d4ec8d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1339,7 +1339,7 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) if (delay > PCI_RESET_WAIT) { if (retrain) { retrain = false; - if (pcie_failed_link_retrain(bridge)) { + if (pcie_failed_link_retrain(bridge) == 0) { delay = 1; continue; } @@ -4732,7 +4732,15 @@ int pcie_retrain_link(struct pci_dev *pdev, bool use_lt) pcie_capability_clear_word(pdev, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_RL); } - return pcie_wait_for_link_status(pdev, use_lt, !use_lt); + rc = pcie_wait_for_link_status(pdev, use_lt, !use_lt); + + /* + * Clear LBMS after a manual retrain so that the bit can be used + * to track link speed or width changes made by hardware itself + * in attempt to correct unreliable link operation. + */ + pcie_capability_write_word(pdev, PCI_EXP_LNKSTA, PCI_EXP_LNKSTA_LBMS); + return rc; } /** diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index fa3771cd8785..665c3b937a55 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -611,7 +611,7 @@ void pci_acs_init(struct pci_dev *dev); int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags); int pci_dev_specific_enable_acs(struct pci_dev *dev); int pci_dev_specific_disable_acs_redir(struct pci_dev *dev); -bool pcie_failed_link_retrain(struct pci_dev *dev); +int pcie_failed_link_retrain(struct pci_dev *dev); #else static inline int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags) @@ -626,9 +626,9 @@ static inline int pci_dev_specific_disable_acs_redir(struct pci_dev *dev) { return -ENOTTY; } -static inline bool pcie_failed_link_retrain(struct pci_dev *dev) +static inline int pcie_failed_link_retrain(struct pci_dev *dev) { - return false; + return -ENOTTY; } #endif diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index a2ce4e08edf5..5d57ea27dbc4 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -66,7 +66,7 @@ * apply this erratum workaround to any downstream ports as long as they * support Link Active reporting and have the Link Control 2 register. * Restrict the speed to 2.5GT/s then with the Target Link Speed field, - * request a retrain and wait 200ms for the data link to go up. + * request a retrain and check the result. * * If this turns out successful and we know by the Vendor:Device ID it is * safe to do so, then lift the restriction, letting the devices negotiate @@ -74,33 +74,45 @@ * firmware may have already arranged and lift it with ports that already * report their data link being up. * - * Return TRUE if the link has been successfully retrained, otherwise FALSE. + * Otherwise revert the speed to the original setting and request a retrain + * again to remove any residual state, ignoring the result as it's supposed + * to fail anyway. + * + * Return 0 if the link has been successfully retrained. Return an error + * if retraining was not needed or we attempted a retrain and it failed. */ -bool pcie_failed_link_retrain(struct pci_dev *dev) +int pcie_failed_link_retrain(struct pci_dev *dev) { static const struct pci_device_id ids[] = { { PCI_VDEVICE(ASMEDIA, 0x2824) }, /* ASMedia ASM2824 */ {} }; u16 lnksta, lnkctl2; + int ret = -ENOTTY; if (!pci_is_pcie(dev) || !pcie_downstream_port(dev) || !pcie_cap_has_lnkctl2(dev) || !dev->link_active_reporting) - return false; + return ret; pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &lnkctl2); pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta); if ((lnksta & (PCI_EXP_LNKSTA_LBMS | PCI_EXP_LNKSTA_DLLLA)) == PCI_EXP_LNKSTA_LBMS) { + u16 oldlnkctl2 = lnkctl2; + pci_info(dev, "broken device, retraining non-functional downstream link at 2.5GT/s\n"); lnkctl2 &= ~PCI_EXP_LNKCTL2_TLS; lnkctl2 |= PCI_EXP_LNKCTL2_TLS_2_5GT; pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, lnkctl2); - if (pcie_retrain_link(dev, false)) { + ret = pcie_retrain_link(dev, false); + if (ret) { pci_info(dev, "retraining failed\n"); - return false; + pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, + oldlnkctl2); + pcie_retrain_link(dev, true); + return ret; } pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta); @@ -117,13 +129,14 @@ bool pcie_failed_link_retrain(struct pci_dev *dev) lnkctl2 |= lnkcap & PCI_EXP_LNKCAP_SLS; pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, lnkctl2); - if (pcie_retrain_link(dev, false)) { + ret = pcie_retrain_link(dev, false); + if (ret) { pci_info(dev, "retraining failed\n"); - return false; + return ret; } } - return true; + return ret; } static ktime_t fixup_debug_start(struct pci_dev *dev, |