Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groec...

[linux-2.6-microblaze.git] / drivers / usb / host / xhci.c

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 5d7d4e9..06fca08 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -577,6 +577,65 @@ static void xhci_restore_registers(struct xhci_hcd *xhci)
        xhci_write_64(xhci, xhci->s3.erst_base, &xhci->ir_set->erst_base);
 }
 
+static void xhci_set_cmd_ring_deq(struct xhci_hcd *xhci)
+{
+       u64     val_64;
+
+       /* step 2: initialize command ring buffer */
+       val_64 = xhci_read_64(xhci, &xhci->op_regs->cmd_ring);
+       val_64 = (val_64 & (u64) CMD_RING_RSVD_BITS) |
+               (xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
+                                     xhci->cmd_ring->dequeue) &
+                (u64) ~CMD_RING_RSVD_BITS) |
+               xhci->cmd_ring->cycle_state;
+       xhci_dbg(xhci, "// Setting command ring address to 0x%llx\n",
+                       (long unsigned long) val_64);
+       xhci_write_64(xhci, val_64, &xhci->op_regs->cmd_ring);
+}
+
+/*
+ * The whole command ring must be cleared to zero when we suspend the host.
+ *
+ * The host doesn't save the command ring pointer in the suspend well, so we
+ * need to re-program it on resume.  Unfortunately, the pointer must be 64-byte
+ * aligned, because of the reserved bits in the command ring dequeue pointer
+ * register.  Therefore, we can't just set the dequeue pointer back in the
+ * middle of the ring (TRBs are 16-byte aligned).
+ */
+static void xhci_clear_command_ring(struct xhci_hcd *xhci)
+{
+       struct xhci_ring *ring;
+       struct xhci_segment *seg;
+
+       ring = xhci->cmd_ring;
+       seg = ring->deq_seg;
+       do {
+               memset(seg->trbs, 0, SEGMENT_SIZE);
+               seg = seg->next;
+       } while (seg != ring->deq_seg);
+
+       /* Reset the software enqueue and dequeue pointers */
+       ring->deq_seg = ring->first_seg;
+       ring->dequeue = ring->first_seg->trbs;
+       ring->enq_seg = ring->deq_seg;
+       ring->enqueue = ring->dequeue;
+
+       /*
+        * Ring is now zeroed, so the HW should look for change of ownership
+        * when the cycle bit is set to 1.
+        */
+       ring->cycle_state = 1;
+
+       /*
+        * Reset the hardware dequeue pointer.
+        * Yes, this will need to be re-written after resume, but we're paranoid
+        * and want to make sure the hardware doesn't access bogus memory
+        * because, say, the BIOS or an SMI started the host without changing
+        * the command ring pointers.
+        */
+       xhci_set_cmd_ring_deq(xhci);
+}
+
 /*
  * Stop HC (not bus-specific)
  *
@@ -604,6 +663,7 @@ int xhci_suspend(struct xhci_hcd *xhci)
                spin_unlock_irq(&xhci->lock);
                return -ETIMEDOUT;
        }
+       xhci_clear_command_ring(xhci);
 
        /* step 3: save registers */
        xhci_save_registers(xhci);
@@ -635,7 +695,6 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
        u32                     command, temp = 0;
        struct usb_hcd          *hcd = xhci_to_hcd(xhci);
        struct pci_dev          *pdev = to_pci_dev(hcd->self.controller);
-       u64     val_64;
        int     old_state, retval;
 
        old_state = hcd->state;
@@ -648,15 +707,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
                /* step 1: restore register */
                xhci_restore_registers(xhci);
                /* step 2: initialize command ring buffer */
-               val_64 = xhci_read_64(xhci, &xhci->op_regs->cmd_ring);
-               val_64 = (val_64 & (u64) CMD_RING_RSVD_BITS) |
-                        (xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
-                                              xhci->cmd_ring->dequeue) &
-                        (u64) ~CMD_RING_RSVD_BITS) |
-                        xhci->cmd_ring->cycle_state;
-               xhci_dbg(xhci, "// Setting command ring address to 0x%llx\n",
-                               (long unsigned long) val_64);
-               xhci_write_64(xhci, val_64, &xhci->op_regs->cmd_ring);
+               xhci_set_cmd_ring_deq(xhci);
                /* step 3: restore state and start state*/
                /* step 3: set CRS flag */
                command = xhci_readl(xhci, &xhci->op_regs->command);
@@ -714,6 +765,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
                return retval;
        }
 
+       spin_unlock_irq(&xhci->lock);
        /* Re-setup MSI-X */
        if (hcd->irq)
                free_irq(hcd->irq, hcd);
@@ -736,6 +788,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
                hcd->irq = pdev->irq;
        }
 
+       spin_lock_irq(&xhci->lock);
        /* step 4: set Run/Stop bit */
        command = xhci_readl(xhci, &xhci->op_regs->command);
        command |= CMD_RUN;