diff mbox series

[v2,2/4] xhci.c: Add polling support for USB keyboards

Message ID 20200914023921.119630-3-jason.wessel@windriver.com
State New
Delegated to: Bin Meng
Headers show
Series xhci fixes for rpi4 | expand

Commit Message

Jason Wessel Sept. 14, 2020, 2:39 a.m. UTC
The xhci driver was causing intermittent 5 second delays from the USB
keyboard polling hook.  Executing something like a "sleep 1" for
example would sleep for 5 seconds, unless an event occurred on
the USB bus to shorten the delay.

Modeled after the code in the DWC2 driver, a nonblock state was added
to quickly return instead of blocking for up to 5 seconds waiting for
an event before timing out.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
 drivers/usb/host/xhci-ring.c | 26 +++++++++++++++++---------
 drivers/usb/host/xhci.c      | 11 ++++++-----
 include/usb/xhci.h           |  5 +++--
 3 files changed, 26 insertions(+), 16 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 092ed6eaf1..607d4f715e 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -432,9 +432,11 @@  static int event_ready(struct xhci_ctrl *ctrl)
  *
  * @param ctrl		Host controller data structure
  * @param expected	TRB type expected from Event TRB
+ * @param nonblock	when true do not block waiting for response
  * @return pointer to event trb
  */
-union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected)
+union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected,
+				    bool nonblock)
 {
 	trb_type type;
 	unsigned long ts = get_timer(0);
@@ -442,8 +444,11 @@  union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected)
 	do {
 		union xhci_trb *event = ctrl->event_ring->dequeue;
 
-		if (!event_ready(ctrl))
+		if (!event_ready(ctrl)) {
+			if (nonblock)
+				return NULL;
 			continue;
+		}
 
 		type = TRB_FIELD_TO_TYPE(le32_to_cpu(event->event_cmd.flags));
 		if (type == expected)
@@ -493,7 +498,7 @@  static void abort_td(struct usb_device *udev, int ep_index)
 
 	xhci_queue_command(ctrl, NULL, udev->slot_id, ep_index, TRB_STOP_RING);
 
-	event = xhci_wait_for_event(ctrl, TRB_TRANSFER);
+	event = xhci_wait_for_event(ctrl, TRB_TRANSFER, false);
 	field = le32_to_cpu(event->trans_event.flags);
 	BUG_ON(TRB_TO_SLOT_ID(field) != udev->slot_id);
 	BUG_ON(TRB_TO_EP_INDEX(field) != ep_index);
@@ -501,7 +506,7 @@  static void abort_td(struct usb_device *udev, int ep_index)
 		!= COMP_STOP)));
 	xhci_acknowledge_event(ctrl);
 
-	event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
+	event = xhci_wait_for_event(ctrl, TRB_COMPLETION, false);
 	BUG_ON(TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags))
 		!= udev->slot_id || GET_COMP_CODE(le32_to_cpu(
 		event->event_cmd.status)) != COMP_SUCCESS);
@@ -509,7 +514,7 @@  static void abort_td(struct usb_device *udev, int ep_index)
 
 	xhci_queue_command(ctrl, (void *)((uintptr_t)ring->enqueue |
 		ring->cycle_state), udev->slot_id, ep_index, TRB_SET_DEQ);
-	event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
+	event = xhci_wait_for_event(ctrl, TRB_COMPLETION, false);
 	BUG_ON(TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags))
 		!= udev->slot_id || GET_COMP_CODE(le32_to_cpu(
 		event->event_cmd.status)) != COMP_SUCCESS);
@@ -552,10 +557,11 @@  static void record_transfer_result(struct usb_device *udev,
  * @param pipe		contains the DIR_IN or OUT , devnum
  * @param length	length of the buffer
  * @param buffer	buffer to be read/written based on the request
+ * @param nonblock	when true do not block waiting for response
  * @return returns 0 if successful else -1 on failure
  */
 int xhci_bulk_tx(struct usb_device *udev, unsigned long pipe,
-			int length, void *buffer)
+			int length, void *buffer, bool nonblock)
 {
 	int num_trbs = 0;
 	struct xhci_generic_trb *start_trb;
@@ -714,8 +720,10 @@  int xhci_bulk_tx(struct usb_device *udev, unsigned long pipe,
 
 	giveback_first_trb(udev, ep_index, start_cycle, start_trb);
 
-	event = xhci_wait_for_event(ctrl, TRB_TRANSFER);
+	event = xhci_wait_for_event(ctrl, TRB_TRANSFER, nonblock);
 	if (!event) {
+		if (nonblock)
+			return -EINVAL;
 		debug("XHCI bulk transfer timed out, aborting...\n");
 		abort_td(udev, ep_index);
 		udev->status = USB_ST_NAK_REC;  /* closest thing to a timeout */
@@ -911,7 +919,7 @@  int xhci_ctrl_tx(struct usb_device *udev, unsigned long pipe,
 
 	giveback_first_trb(udev, ep_index, start_cycle, start_trb);
 
-	event = xhci_wait_for_event(ctrl, TRB_TRANSFER);
+	event = xhci_wait_for_event(ctrl, TRB_TRANSFER, false);
 	if (!event)
 		goto abort;
 	field = le32_to_cpu(event->trans_event.flags);
@@ -929,7 +937,7 @@  int xhci_ctrl_tx(struct usb_device *udev, unsigned long pipe,
 	if (GET_COMP_CODE(le32_to_cpu(event->trans_event.transfer_len))
 			== COMP_SHORT_TX) {
 		/* Short data stage, clear up additional status stage event */
-		event = xhci_wait_for_event(ctrl, TRB_TRANSFER);
+		event = xhci_wait_for_event(ctrl, TRB_TRANSFER, false);
 		if (!event)
 			goto abort;
 		BUG_ON(TRB_TO_SLOT_ID(field) != slot_id);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 9a31eba2bb..3a359f0adc 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -495,7 +495,7 @@  static int xhci_configure_endpoints(struct usb_device *udev, bool ctx_change)
 	xhci_flush_cache((uintptr_t)in_ctx->bytes, in_ctx->size);
 	xhci_queue_command(ctrl, in_ctx->bytes, udev->slot_id, 0,
 			   ctx_change ? TRB_EVAL_CONTEXT : TRB_CONFIG_EP);
-	event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
+	event = xhci_wait_for_event(ctrl, TRB_COMPLETION, false);
 	BUG_ON(TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags))
 		!= udev->slot_id);
 
@@ -692,7 +692,7 @@  retry:
 	ctrl_ctx->drop_flags = 0;
 
 	xhci_queue_command(ctrl, (void *)ctrl_ctx, slot_id, 0, TRB_ADDR_DEV);
-	event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
+	event = xhci_wait_for_event(ctrl, TRB_COMPLETION, false);
 	BUG_ON(TRB_TO_SLOT_ID(le32_to_cpu(event->event_cmd.flags)) != slot_id);
 
 	switch (GET_COMP_CODE(le32_to_cpu(event->event_cmd.status))) {
@@ -774,7 +774,7 @@  static int _xhci_alloc_device(struct usb_device *udev)
 	}
 
 	xhci_queue_command(ctrl, NULL, 0, 0, TRB_ENABLE_SLOT);
-	event = xhci_wait_for_event(ctrl, TRB_COMPLETION);
+	event = xhci_wait_for_event(ctrl, TRB_COMPLETION, false);
 	BUG_ON(GET_COMP_CODE(le32_to_cpu(event->event_cmd.status))
 		!= COMP_SUCCESS);
 
@@ -1160,6 +1160,7 @@  unknown:
  * @param buffer	buffer to be read/written based on the request
  * @param length	length of the buffer
  * @param interval	interval of the interrupt
+ * @param nonblock	when true do not block waiting for response
  * @return 0
  */
 static int _xhci_submit_int_msg(struct usb_device *udev, unsigned long pipe,
@@ -1177,7 +1178,7 @@  static int _xhci_submit_int_msg(struct usb_device *udev, unsigned long pipe,
 	 * (at most) one TD. A TD (comprised of sg list entries) can
 	 * take several service intervals to transmit.
 	 */
-	return xhci_bulk_tx(udev, pipe, length, buffer);
+	return xhci_bulk_tx(udev, pipe, length, buffer, nonblock);
 }
 
 /**
@@ -1197,7 +1198,7 @@  static int _xhci_submit_bulk_msg(struct usb_device *udev, unsigned long pipe,
 		return -EINVAL;
 	}
 
-	return xhci_bulk_tx(udev, pipe, length, buffer);
+	return xhci_bulk_tx(udev, pipe, length, buffer, false);
 }
 
 /**
diff --git a/include/usb/xhci.h b/include/usb/xhci.h
index 7d34103fd5..73db77fc02 100644
--- a/include/usb/xhci.h
+++ b/include/usb/xhci.h
@@ -1249,9 +1249,10 @@  void xhci_setup_addressable_virt_dev(struct xhci_ctrl *ctrl,
 void xhci_queue_command(struct xhci_ctrl *ctrl, u8 *ptr,
 			u32 slot_id, u32 ep_index, trb_type cmd);
 void xhci_acknowledge_event(struct xhci_ctrl *ctrl);
-union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected);
+union xhci_trb *xhci_wait_for_event(struct xhci_ctrl *ctrl, trb_type expected,
+				    bool nonblock);
 int xhci_bulk_tx(struct usb_device *udev, unsigned long pipe,
-		 int length, void *buffer);
+		 int length, void *buffer, bool nonblock);
 int xhci_ctrl_tx(struct usb_device *udev, unsigned long pipe,
 		 struct devrequest *req, int length, void *buffer);
 int xhci_check_maxpacket(struct usb_device *udev);