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path: root/drivers/usb/host/xhci.c
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Diffstat (limited to 'drivers/usb/host/xhci.c')
-rw-r--r--drivers/usb/host/xhci.c73
1 files changed, 63 insertions, 10 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 5d7d4e951ea4..06fca0835b52 100644
--- 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;