| Message ID | 20240613054204.5850-3-mario.limonciello@amd.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | Verify devices transition from D3cold to D0 | expand |
… > As PCIe r6.0 sec 5.8 specifies that the device will have gone > through a conventional reset it may take some time for the > device to be ready. > > Wait up to 1 sec as specified in PCIe r6.0 sec 6.6.1 for a device > in D3cold to return to D0. Would you like to add the tag “Fixes” accordingly? Regards, Markus
On 6/19/2024 13:45, Markus Elfring wrote: > … >> As PCIe r6.0 sec 5.8 specifies that the device will have gone >> through a conventional reset it may take some time for the >> device to be ready. >> >> Wait up to 1 sec as specified in PCIe r6.0 sec 6.6.1 for a device >> in D3cold to return to D0. > > Would you like to add the tag “Fixes” accordingly? > > Regards, > Markus The first patch is a strong dependency for this to work, and if we don't bring the first patch back automatically we shouldn't do this one.
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 41961e28a86c..a6ed85dd8d92 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1387,6 +1387,17 @@ int pci_power_up(struct pci_dev *dev) else if (state == PCI_D2) udelay(PCI_PM_D2_DELAY); + /* + * D3cold -> D0 will have gone through a conventional reset and may need + * time to be ready. + */ + if (dev->current_state == PCI_D3cold) { + int ret; + + ret = pci_dev_wait(dev, "D3cold->D0", PCI_RESET_WAIT); + if (ret) + return ret; + } end: dev->current_state = PCI_D0; if (need_restore)
It is reported that USB4 routers and downstream devices may behave incorrectly if a dock cable is plugged in at approximately the time that the autosuspend_delay is configured. In this situation the device has attempted to enter D3cold, but didn't finish D3cold entry when the PCI core tried to transition it back to D0. Empirically measuring this situation an "aborted" D3cold exit takes ~60ms and a "normal" D3cold exit takes ~10ms. The PCI-PM 1.2 spec specifies that the restore time for functions in D3cold is either 'Full context restore or boot latency'. As PCIe r6.0 sec 5.8 specifies that the device will have gone through a conventional reset it may take some time for the device to be ready. Wait up to 1 sec as specified in PCIe r6.0 sec 6.6.1 for a device in D3cold to return to D0. Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> --- drivers/pci/pci.c | 11 +++++++++++ 1 file changed, 11 insertions(+)