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path: root/drivers/pci/hotplug/pciehp_hpc.c
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Diffstat (limited to 'drivers/pci/hotplug/pciehp_hpc.c')
-rw-r--r--drivers/pci/hotplug/pciehp_hpc.c133
1 files changed, 109 insertions, 24 deletions
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index bcdbb1643621..a960faec1021 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -241,34 +241,79 @@ static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
return retval;
}
-static inline int check_link_active(struct controller *ctrl)
+static bool check_link_active(struct controller *ctrl)
{
- u16 link_status;
+ bool ret = false;
+ u16 lnk_status;
- if (pciehp_readw(ctrl, PCI_EXP_LNKSTA, &link_status))
- return 0;
- return !!(link_status & PCI_EXP_LNKSTA_DLLLA);
+ if (pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status))
+ return ret;
+
+ ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
+
+ if (ret)
+ ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
+
+ return ret;
}
-static void pcie_wait_link_active(struct controller *ctrl)
+static void __pcie_wait_link_active(struct controller *ctrl, bool active)
{
int timeout = 1000;
- if (check_link_active(ctrl))
+ if (check_link_active(ctrl) == active)
return;
while (timeout > 0) {
msleep(10);
timeout -= 10;
- if (check_link_active(ctrl))
+ if (check_link_active(ctrl) == active)
return;
}
- ctrl_dbg(ctrl, "Data Link Layer Link Active not set in 1000 msec\n");
+ ctrl_dbg(ctrl, "Data Link Layer Link Active not %s in 1000 msec\n",
+ active ? "set" : "cleared");
+}
+
+static void pcie_wait_link_active(struct controller *ctrl)
+{
+ __pcie_wait_link_active(ctrl, true);
+}
+
+static void pcie_wait_link_not_active(struct controller *ctrl)
+{
+ __pcie_wait_link_active(ctrl, false);
+}
+
+static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)
+{
+ u32 l;
+ int count = 0;
+ int delay = 1000, step = 20;
+ bool found = false;
+
+ do {
+ found = pci_bus_read_dev_vendor_id(bus, devfn, &l, 0);
+ count++;
+
+ if (found)
+ break;
+
+ msleep(step);
+ delay -= step;
+ } while (delay > 0);
+
+ if (count > 1 && pciehp_debug)
+ printk(KERN_DEBUG "pci %04x:%02x:%02x.%d id reading try %d times with interval %d ms to get %08x\n",
+ pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
+ PCI_FUNC(devfn), count, step, l);
+
+ return found;
}
int pciehp_check_link_status(struct controller *ctrl)
{
u16 lnk_status;
int retval = 0;
+ bool found = false;
/*
* Data Link Layer Link Active Reporting must be capable for
@@ -280,13 +325,10 @@ int pciehp_check_link_status(struct controller *ctrl)
else
msleep(1000);
- /*
- * Need to wait for 1000 ms after Data Link Layer Link Active
- * (DLLLA) bit reads 1b before sending configuration request.
- * We need it before checking Link Training (LT) bit becuase
- * LT is still set even after DLLLA bit is set on some platform.
- */
- msleep(1000);
+ /* 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));
retval = pciehp_readw(ctrl, PCI_EXP_LNKSTA, &lnk_status);
if (retval) {
@@ -302,19 +344,50 @@ int pciehp_check_link_status(struct controller *ctrl)
return retval;
}
- /*
- * If the port supports Link speeds greater than 5.0 GT/s, we
- * must wait for 100 ms after Link training completes before
- * sending configuration request.
- */
- if (ctrl->pcie->port->subordinate->max_bus_speed > PCIE_SPEED_5_0GT)
- msleep(100);
-
pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
+ if (!found && !retval)
+ retval = -1;
+
return retval;
}
+static int __pciehp_link_set(struct controller *ctrl, bool enable)
+{
+ u16 lnk_ctrl;
+ int retval = 0;
+
+ retval = pciehp_readw(ctrl, PCI_EXP_LNKCTL, &lnk_ctrl);
+ if (retval) {
+ ctrl_err(ctrl, "Cannot read LNKCTRL register\n");
+ return retval;
+ }
+
+ if (enable)
+ lnk_ctrl &= ~PCI_EXP_LNKCTL_LD;
+ else
+ lnk_ctrl |= PCI_EXP_LNKCTL_LD;
+
+ retval = pciehp_writew(ctrl, PCI_EXP_LNKCTL, lnk_ctrl);
+ if (retval) {
+ ctrl_err(ctrl, "Cannot write LNKCTRL register\n");
+ return retval;
+ }
+ ctrl_dbg(ctrl, "%s: lnk_ctrl = %x\n", __func__, lnk_ctrl);
+
+ return retval;
+}
+
+static int pciehp_link_enable(struct controller *ctrl)
+{
+ return __pciehp_link_set(ctrl, true);
+}
+
+static int pciehp_link_disable(struct controller *ctrl)
+{
+ return __pciehp_link_set(ctrl, false);
+}
+
int pciehp_get_attention_status(struct slot *slot, u8 *status)
{
struct controller *ctrl = slot->ctrl;
@@ -533,6 +606,10 @@ int pciehp_power_on_slot(struct slot * slot)
ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
+ retval = pciehp_link_enable(ctrl);
+ if (retval)
+ ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__);
+
return retval;
}
@@ -543,6 +620,14 @@ int pciehp_power_off_slot(struct slot * slot)
u16 cmd_mask;
int retval;
+ /* Disable the link at first */
+ pciehp_link_disable(ctrl);
+ /* wait the link is down */
+ if (ctrl->link_active_reporting)
+ pcie_wait_link_not_active(ctrl);
+ else
+ msleep(1000);
+
slot_cmd = POWER_OFF;
cmd_mask = PCI_EXP_SLTCTL_PCC;
retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);