1 files changed, 45 insertions, 56 deletions

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 42914e04d110..9da84b8b27d8 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -104,11 +104,10 @@ static inline void pciehp_free_irq(struct controller *ctrl)
                 free_irq(ctrl->pcie->irq, ctrl);
 }
 
-static int pcie_poll_cmd(struct controller *ctrl)
+static int pcie_poll_cmd(struct controller *ctrl, int timeout)
 {
         struct pci_dev *pdev = ctrl_dev(ctrl);
         u16 slot_status;
-        int timeout = 1000;
 
         pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
         if (slot_status & PCI_EXP_SLTSTA_CC) {
@@ -129,18 +128,52 @@ static int pcie_poll_cmd(struct controller *ctrl)
         return 0;       /* timeout */
 }
 
-static void pcie_wait_cmd(struct controller *ctrl, int poll)
+static void pcie_wait_cmd(struct controller *ctrl)
 {
         unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
-        unsigned long timeout = msecs_to_jiffies(msecs);
+        unsigned long duration = msecs_to_jiffies(msecs);
+        unsigned long cmd_timeout = ctrl->cmd_started + duration;
+        unsigned long now, timeout;
         int rc;
 
-        if (poll)
-                rc = pcie_poll_cmd(ctrl);
+        /*
+         * If the controller does not generate notifications for command
+         * completions, we never need to wait between writes.
+         */
+        if (NO_CMD_CMPL(ctrl))
+                return;
+
+        if (!ctrl->cmd_busy)
+                return;
+
+        /*
+         * Even if the command has already timed out, we want to call
+         * pcie_poll_cmd() so it can clear PCI_EXP_SLTSTA_CC.
+         */
+        now = jiffies;
+        if (time_before_eq(cmd_timeout, now))
+                timeout = 1;
         else
+                timeout = cmd_timeout - now;
+
+        if (ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE &&
+            ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE)
                 rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
+        else
+                rc = pcie_poll_cmd(ctrl, timeout);
+
+        /*
+         * Controllers with errata like Intel CF118 don't generate
+         * completion notifications unless the power/indicator/interlock
+         * control bits are changed.  On such controllers, we'll emit this
+         * timeout message when we wait for completion of commands that
+         * don't change those bits, e.g., commands that merely enable
+         * interrupts.
+         */
         if (!rc)
-                ctrl_dbg(ctrl, "Command not completed in 1000 msec\n");
+                ctrl_info(ctrl, "Timeout on hotplug command %#010x (issued %u msec ago)\n",
+                          ctrl->slot_ctrl,
+                          jiffies_to_msecs(now - ctrl->cmd_started));
 }
 
 /**
@@ -152,34 +185,12 @@ static void pcie_wait_cmd(struct controller *ctrl, int poll)
 static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
 {
         struct pci_dev *pdev = ctrl_dev(ctrl);
-        u16 slot_status;
         u16 slot_ctrl;
 
         mutex_lock(&ctrl->ctrl_lock);
 
-        pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
-        if (slot_status & PCI_EXP_SLTSTA_CC) {
-                pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
-                                           PCI_EXP_SLTSTA_CC);
-                if (!ctrl->no_cmd_complete) {
-                        /*
-                         * After 1 sec and CMD_COMPLETED still not set, just
-                         * proceed forward to issue the next command according
-                         * to spec. Just print out the error message.
-                         */
-                        ctrl_dbg(ctrl, "CMD_COMPLETED not clear after 1 sec\n");
-                } else if (!NO_CMD_CMPL(ctrl)) {
-                        /*
-                         * This controller seems to notify of command completed
-                         * event even though it supports none of power
-                         * controller, attention led, power led and EMI.
-                         */
-                        ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Need to wait for command completed event\n");
-                        ctrl->no_cmd_complete = 0;
-                } else {
-                        ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Maybe the controller is broken\n");
-                }
-        }
+        /* Wait for any previous command that might still be in progress */
+        pcie_wait_cmd(ctrl);
 
         pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
         slot_ctrl &= ~mask;
@@ -187,22 +198,9 @@ static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
         ctrl->cmd_busy = 1;
         smp_mb();
         pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl);
+        ctrl->cmd_started = jiffies;
+        ctrl->slot_ctrl = slot_ctrl;
 
-        /*
-         * Wait for command completion.
-         */
-        if (!ctrl->no_cmd_complete) {
-                int poll = 0;
-                /*
-                 * if hotplug interrupt is not enabled or command
-                 * completed interrupt is not enabled, we need to poll
-                 * command completed event.
-                 */
-                if (!(slot_ctrl & PCI_EXP_SLTCTL_HPIE) ||
-                    !(slot_ctrl & PCI_EXP_SLTCTL_CCIE))
-                        poll = 1;
-                pcie_wait_cmd(ctrl, poll);
-        }
         mutex_unlock(&ctrl->ctrl_lock);
 }
 
@@ -773,15 +771,6 @@ struct controller *pcie_init(struct pcie_device *dev)
         mutex_init(&ctrl->ctrl_lock);
         init_waitqueue_head(&ctrl->queue);
         dbg_ctrl(ctrl);
-        /*
-         * Controller doesn't notify of command completion if the "No
-         * Command Completed Support" bit is set in Slot Capability
-         * register or the controller supports none of power
-         * controller, attention led, power led and EMI.
-         */
-        if (NO_CMD_CMPL(ctrl) ||
-            !(POWER_CTRL(ctrl) | ATTN_LED(ctrl) | PWR_LED(ctrl) | EMI(ctrl)))
-                ctrl->no_cmd_complete = 1;
 
         /* Check if Data Link Layer Link Active Reporting is implemented */
         pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
@@ -794,7 +783,7 @@ struct controller *pcie_init(struct pcie_device *dev)
         pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
                 PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
                 PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
-                PCI_EXP_SLTSTA_CC);
+                PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
 
         /* Disable software notification */
         pcie_disable_notification(ctrl);