usb: xhci: remove 'num_trbs' from struct 'xhci_td'

Remove 'num_trbs' from 'xhci_td' as it's no longer used following the
removal of 'num_trbs_free' tracking in commit 2710f818 ("xhci: Stop
unnecessary tracking of free trbs in a ring").

Tracking of 'num_trbs_free' is still performed in xhci DbC, but it does not
utilize 'num_trbs'.
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240626124835.1023046-6-mathias.nyman@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-ring.c

@@ -3704,7 +3704,6 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 				upper_32_bits(send_addr),
 				length_field,
 				field);
-		td->num_trbs++;
 		addr += trb_buff_len;
 		sent_len = trb_buff_len;
 
@@ -3731,7 +3730,6 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 		urb_priv->td[1].last_trb_seg = ring->enq_seg;
 		field = TRB_TYPE(TRB_NORMAL) | ring->cycle_state | TRB_IOC;
 		queue_trb(xhci, ring, 0, 0, 0, TRB_INTR_TARGET(0), field);
-		urb_priv->td[1].num_trbs++;
 	}
 
 	check_trb_math(urb, enqd_len);
@@ -3782,7 +3780,6 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 
 	urb_priv = urb->hcpriv;
 	td = &urb_priv->td[0];
-	td->num_trbs = num_trbs;
 
 	/*
 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
@@ -4103,7 +4100,6 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 			goto cleanup;
 		}
 		td = &urb_priv->td[i];
-		td->num_trbs = trbs_per_td;
 		/* use SIA as default, if frame id is used overwrite it */
 		sia_frame_id = TRB_SIA;
 		if (!(urb->transfer_flags & URB_ISO_ASAP) &&

drivers/usb/host/xhci.h

@@ -1295,7 +1295,6 @@ struct xhci_td {
 	/* actual_length of the URB has already been set */
 	bool			urb_length_set;
 	bool			error_mid_td;
-	unsigned int		num_trbs;
 };
 
 /*