USB: xhci: Add quirk for Fresco Logic xHCI hardware.

This Fresco Logic xHCI host controller chip revision puts bad data into
the output endpoint context after a Reset Endpoint command.  It needs a
Configure Endpoint command (instead of a Set TR Dequeue Pointer command)
after the reset endpoint command.

Set up the input context before issuing the Reset Endpoint command so we
don't copy bad data from the output endpoint context.  The HW also can't
handle two commands queued at once, so submit the TRB for the Configure
Endpoint command in the event handler for the Reset Endpoint command.

Devices that stall on control endpoints before a configuration is selected
will not work under this Fresco Logic xHCI host controller revision.

This patch is for prototype hardware that will be given to other companies
for evaluation purposes only, and should not reach consumer hands.  Fresco
Logic's next chip rev should have this bug fixed.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 68 insertions, 9 deletions

diff --git a/drivers/usb/host/xhci-hcd.c b/drivers/usb/host/xhci-hcd.c
index 4353c1c78935..1d4a1e3f9533 100644
--- a/drivers/usb/host/xhci-hcd.c
+++ b/drivers/usb/host/xhci-hcd.c
@@ -224,7 +224,7 @@ int xhci_init(struct usb_hcd *hcd)
                 xhci_dbg(xhci, "QUIRK: Not clearing Link TRB chain bits.\n");
                 xhci->quirks |= XHCI_LINK_TRB_QUIRK;
         } else {
-                xhci_dbg(xhci, "xHCI has no QUIRKS\n");
+                xhci_dbg(xhci, "xHCI doesn't need link TRB QUIRK\n");
         }
         retval = xhci_mem_init(xhci, GFP_KERNEL);
         xhci_dbg(xhci, "Finished xhci_init\n");
@@ -567,13 +567,22 @@ unsigned int xhci_get_endpoint_flag(struct usb_endpoint_descriptor *desc)
         return 1 << (xhci_get_endpoint_index(desc) + 1);
 }
 
+/* Find the flag for this endpoint (for use in the control context).  Use the
+ * endpoint index to create a bitmask.  The slot context is bit 0, endpoint 0 is
+ * bit 1, etc.
+ */
+unsigned int xhci_get_endpoint_flag_from_index(unsigned int ep_index)
+{
+        return 1 << (ep_index + 1);
+}
+
 /* Compute the last valid endpoint context index.  Basically, this is the
  * endpoint index plus one.  For slot contexts with more than valid endpoint,
  * we find the most significant bit set in the added contexts flags.
  * e.g. ep 1 IN (with epnum 0x81) => added_ctxs = 0b1000
  * fls(0b1000) = 4, but the endpoint context index is 3, so subtract one.
  */
-static inline unsigned int xhci_last_valid_endpoint(u32 added_ctxs)
+unsigned int xhci_last_valid_endpoint(u32 added_ctxs)
 {
         return fls(added_ctxs) - 1;
 }
@@ -1230,8 +1239,44 @@ void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
         xhci_zero_in_ctx(xhci, virt_dev);
 }
 
+void xhci_setup_input_ctx_for_quirk(struct xhci_hcd *xhci,
+                unsigned int slot_id, unsigned int ep_index,
+                struct xhci_dequeue_state *deq_state)
+{
+        struct xhci_container_ctx *in_ctx;
+        struct xhci_input_control_ctx *ctrl_ctx;
+        struct xhci_ep_ctx *ep_ctx;
+        u32 added_ctxs;
+        dma_addr_t addr;
+
+        xhci_endpoint_copy(xhci, xhci->devs[slot_id], ep_index);
+        in_ctx = xhci->devs[slot_id]->in_ctx;
+        ep_ctx = xhci_get_ep_ctx(xhci, in_ctx, ep_index);
+        addr = xhci_trb_virt_to_dma(deq_state->new_deq_seg,
+                        deq_state->new_deq_ptr);
+        if (addr == 0) {
+                xhci_warn(xhci, "WARN Cannot submit config ep after "
+                                "reset ep command\n");
+                xhci_warn(xhci, "WARN deq seg = %p, deq ptr = %p\n",
+                                deq_state->new_deq_seg,
+                                deq_state->new_deq_ptr);
+                return;
+        }
+        ep_ctx->deq = addr | deq_state->new_cycle_state;
+
+        xhci_slot_copy(xhci, xhci->devs[slot_id]);
+
+        ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx);
+        added_ctxs = xhci_get_endpoint_flag_from_index(ep_index);
+        ctrl_ctx->add_flags = added_ctxs | SLOT_FLAG;
+        ctrl_ctx->drop_flags = added_ctxs;
+
+        xhci_dbg(xhci, "Slot ID %d Input Context:\n", slot_id);
+        xhci_dbg_ctx(xhci, in_ctx, ep_index);
+}
+
 void xhci_cleanup_stalled_ring(struct xhci_hcd *xhci,
-                struct usb_device *udev, struct usb_host_endpoint *ep,
+                struct usb_device *udev,
                 unsigned int ep_index, struct xhci_ring *ep_ring)
 {
         struct xhci_dequeue_state deq_state;
@@ -1241,12 +1286,26 @@ void xhci_cleanup_stalled_ring(struct xhci_hcd *xhci,
          * or it will attempt to resend it on the next doorbell ring.
          */
         xhci_find_new_dequeue_state(xhci, udev->slot_id,
-                        ep_index, ep_ring->stopped_td, &deq_state);
+                        ep_index, ep_ring->stopped_td,
+                        &deq_state);
 
-        xhci_dbg(xhci, "Queueing new dequeue state\n");
-        xhci_queue_new_dequeue_state(xhci, ep_ring,
-                        udev->slot_id,
-                        ep_index, &deq_state);
+        /* HW with the reset endpoint quirk will use the saved dequeue state to
+         * issue a configure endpoint command later.
+         */
+        if (!(xhci->quirks & XHCI_RESET_EP_QUIRK)) {
+                xhci_dbg(xhci, "Queueing new dequeue state\n");
+                xhci_queue_new_dequeue_state(xhci, ep_ring,
+                                udev->slot_id,
+                                ep_index, &deq_state);
+        } else {
+                /* Better hope no one uses the input context between now and the
+                 * reset endpoint completion!
+                 */
+                xhci_dbg(xhci, "Setting up input context for "
+                                "configure endpoint command\n");
+                xhci_setup_input_ctx_for_quirk(xhci, udev->slot_id,
+                                ep_index, &deq_state);
+        }
 }
 
 /* Deal with stalled endpoints.  The core should have sent the control message
@@ -1293,7 +1352,7 @@ void xhci_endpoint_reset(struct usb_hcd *hcd,
          * command.  Better hope that last command worked!
          */
         if (!ret) {
-                xhci_cleanup_stalled_ring(xhci, udev, ep, ep_index, ep_ring);
+                xhci_cleanup_stalled_ring(xhci, udev, ep_index, ep_ring);
                 kfree(ep_ring->stopped_td);
                 xhci_ring_cmd_db(xhci);
         }