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PCI: Make link active reporting detection generic

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The spec has timing requirements when waiting for a link to become active
after a conventional reset.  Implement those hard delays when waiting for
an active link so pciehp and dpc drivers don't need to duplicate this.

For devices that don't support data link layer active reporting, wait the
fixed time recommended by the PCIe spec.

Signed-off-by: Keith Busch <keith.busch@intel.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
This commit is contained in:
Keith Busch
2018-09-20 10:27:17 -06:00
committed by Bjorn Helgaas
parent a6bd101b8f
commit f0157160b3
6 changed files with 34 additions and 33 deletions
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22
drivers/pci/hotplug/pciehp_hpc.c
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@@ -214,13 +214,6 @@ bool pciehp_check_link_active(struct controller *ctrl)
return ret;
}
static void pcie_wait_link_active(struct controller *ctrl)
{
struct pci_dev *pdev = ctrl_dev(ctrl);
pcie_wait_for_link(pdev, true);
}
static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)
{
u32 l;
@@ -253,18 +246,9 @@ int pciehp_check_link_status(struct controller *ctrl)
bool found;
u16 lnk_status;
/*
* Data Link Layer Link Active Reporting must be capable for
* hot-plug capable downstream port. But old controller might
* not implement it. In this case, we wait for 1000 ms.
*/
if (ctrl->link_active_reporting)
pcie_wait_link_active(ctrl);
else
msleep(1000);
if (!pcie_wait_for_link(pdev, true))
return -1;
/* wait 100ms before read pci conf, and try in 1s */
msleep(100);
found = pci_bus_check_dev(ctrl->pcie->port->subordinate,
PCI_DEVFN(0, 0));
@@ -865,8 +849,6 @@ struct controller *pcie_init(struct pcie_device *dev)
/* Check if Data Link Layer Link Active Reporting is implemented */
pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
if (link_cap & PCI_EXP_LNKCAP_DLLLARC)
ctrl->link_active_reporting = 1;
/* Clear all remaining event bits in Slot Status register. */
pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,