Revert "xhci: replace xhci_write_64() with writeq()"

This reverts commit 7dd09a1af2c7150269350aaa567a11b06e831003.

Many xHCI host controllers can only handle 32-bit addresses, and writing
64-bits at a time causes them to fail.  Rafał reports that USB devices
simply do not enumerate, and reverting this patch helps.  Branimir
reports that his host controller doesn't respond to an Enable Slot
command and dies:

[   75.576160] xhci_hcd 0000:03:00.0: Timeout while waiting for a slot
[   88.991634] xhci_hcd 0000:03:00.0: Stopped the command ring failed, maybe the host is dead
[   88.991748] xhci_hcd 0000:03:00.0: Abort command ring failed
[   88.991845] xhci_hcd 0000:03:00.0: HC died; cleaning up
[   93.985489] xhci_hcd 0000:03:00.0: Timeout while waiting for a slot
[   93.985494] xhci_hcd 0000:03:00.0: Abort the command ring, but the xHCI is dead.
[   98.982586] xhci_hcd 0000:03:00.0: Timeout while waiting for a slot
[   98.982591] xhci_hcd 0000:03:00.0: Abort the command ring, but the xHCI is dead.
[  103.979696] xhci_hcd 0000:03:00.0: Timeout while waiting for a slot
[  103.979702] xhci_hcd 0000:03:00.0: Abort the command ring, but the xHCI is dead

Signed-off-by: Sarah Sharp <sarah.a.sharp@intel.com>
Reported-by: Rafał Miłecki <zajec5@gmail.com>
Reported-by: Branimir Maksimovic <branimir.maksimovic@gmail.com>
Cc: Xenia Ragiadakou <burzalodowa@gmail.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index a0b248c34526..e19fae964f76 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -313,7 +313,8 @@ static int xhci_abort_cmd_ring(struct xhci_hcd *xhci)
                 return 0;
         }
         xhci->cmd_ring_state = CMD_RING_STATE_ABORTED;
-        writeq(temp_64 | CMD_RING_ABORT, &xhci->op_regs->cmd_ring);
+        xhci_write_64(xhci, temp_64 | CMD_RING_ABORT,
+                        &xhci->op_regs->cmd_ring);
 
         /* Section 4.6.1.2 of xHCI 1.0 spec says software should
          * time the completion od all xHCI commands, including
@@ -2865,7 +2866,8 @@ hw_died:
                  * the event ring should be empty.
                  */
                 temp_64 = readq(&xhci->ir_set->erst_dequeue);
-                writeq(temp_64 | ERST_EHB, &xhci->ir_set->erst_dequeue);
+                xhci_write_64(xhci, temp_64 | ERST_EHB,
+                                &xhci->ir_set->erst_dequeue);
                 spin_unlock(&xhci->lock);
 
                 return IRQ_HANDLED;
@@ -2892,7 +2894,7 @@ hw_died:
 
         /* Clear the event handler busy flag (RW1C); event ring is empty. */
         temp_64 |= ERST_EHB;
-        writeq(temp_64, &xhci->ir_set->erst_dequeue);
+        xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue);
 
         spin_unlock(&xhci->lock);