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authorBjorn Helgaas <bhelgaas@google.com>2020-06-04 19:59:12 +0200
committerBjorn Helgaas <bhelgaas@google.com>2020-06-04 19:59:12 +0200
commitae7322a06d225fadfc43a3eda950fc2b65d2d7a1 (patch)
tree5c20dfad6d9e1218752433542d7e10b308bd5394 /drivers/pci/pci.c
parentMerge branch 'pci/p2pdma' (diff)
parentPCI/PM: Assume ports without DLL Link Active train links in 100 ms (diff)
downloadlinux-ae7322a06d225fadfc43a3eda950fc2b65d2d7a1.tar.xz
linux-ae7322a06d225fadfc43a3eda950fc2b65d2d7a1.zip
Merge branch 'pci/pm'
- Check .bridge_d3() hook for NULL before calling it (Bjorn Helgaas) - Disable PME# for Pericom OHCI/UHCI USB controllers because it's not reliably asserted on USB hotplug (Kai-Heng Feng) - Assume ports without DLL Link Active train links in 100 ms to work around Thunderbolt bridge defects (Mika Westerberg) * pci/pm: PCI/PM: Assume ports without DLL Link Active train links in 100 ms PCI/PM: Adjust pcie_wait_for_link_delay() for caller delay PCI: Avoid Pericom USB controller OHCI/EHCI PME# defect serial: 8250_pci: Move Pericom IDs to pci_ids.h PCI/PM: Call .bridge_d3() hook only if non-NULL
Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c38
1 files changed, 26 insertions, 12 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 227a3a979ec4..ce096272f52b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -844,7 +844,9 @@ static inline bool platform_pci_need_resume(struct pci_dev *dev)
static inline bool platform_pci_bridge_d3(struct pci_dev *dev)
{
- return pci_platform_pm ? pci_platform_pm->bridge_d3(dev) : false;
+ if (pci_platform_pm && pci_platform_pm->bridge_d3)
+ return pci_platform_pm->bridge_d3(dev);
+ return false;
}
/**
@@ -4636,7 +4638,8 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
* pcie_wait_for_link_delay - Wait until link is active or inactive
* @pdev: Bridge device
* @active: waiting for active or inactive?
- * @delay: Delay to wait after link has become active (in ms)
+ * @delay: Delay to wait after link has become active (in ms). Specify %0
+ * for no delay.
*
* Use this to wait till link becomes active or inactive.
*/
@@ -4649,10 +4652,10 @@ static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,
/*
* Some controllers might not implement link active reporting. In this
- * case, we wait for 1000 + 100 ms.
+ * case, we wait for 1000 ms + any delay requested by the caller.
*/
if (!pdev->link_active_reporting) {
- msleep(1100);
+ msleep(timeout + delay);
return true;
}
@@ -4677,7 +4680,7 @@ static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,
msleep(10);
timeout -= 10;
}
- if (active && ret)
+ if (active && ret && delay)
msleep(delay);
else if (ret != active)
pci_info(pdev, "Data Link Layer Link Active not %s in 1000 msec\n",
@@ -4798,17 +4801,28 @@ void pci_bridge_wait_for_secondary_bus(struct pci_dev *dev)
if (!pcie_downstream_port(dev))
return;
- if (pcie_get_speed_cap(dev) <= PCIE_SPEED_5_0GT) {
- pci_dbg(dev, "waiting %d ms for downstream link\n", delay);
- msleep(delay);
- } else {
- pci_dbg(dev, "waiting %d ms for downstream link, after activation\n",
- delay);
- if (!pcie_wait_for_link_delay(dev, true, delay)) {
+ /*
+ * Per PCIe r5.0, sec 6.6.1, for downstream ports that support
+ * speeds > 5 GT/s, we must wait for link training to complete
+ * before the mandatory delay.
+ *
+ * We can only tell when link training completes via DLL Link
+ * Active, which is required for downstream ports that support
+ * speeds > 5 GT/s (sec 7.5.3.6). Unfortunately some common
+ * devices do not implement Link Active reporting even when it's
+ * required, so we'll check for that directly instead of checking
+ * the supported link speed. We assume devices without Link Active
+ * reporting can train in 100 ms regardless of speed.
+ */
+ if (dev->link_active_reporting) {
+ pci_dbg(dev, "waiting for link to train\n");
+ if (!pcie_wait_for_link_delay(dev, true, 0)) {
/* Did not train, no need to wait any further */
return;
}
}
+ pci_dbg(child, "waiting %d ms to become accessible\n", delay);
+ msleep(delay);
if (!pci_device_is_present(child)) {
pci_dbg(child, "waiting additional %d ms to become accessible\n", delay);