From 1543e317f1da31b75942316931e8f491a8920811 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Thu, 04 Jan 2024 10:08:02 +0000
Subject: [PATCH] disable FB

---
 kernel/drivers/net/can/usb/gs_usb.c |   56 +++++++++++++++++++++++++++++++++++---------------------
 1 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/kernel/drivers/net/can/usb/gs_usb.c b/kernel/drivers/net/can/usb/gs_usb.c
index 8fa5836..864db20 100644
--- a/kernel/drivers/net/can/usb/gs_usb.c
+++ b/kernel/drivers/net/can/usb/gs_usb.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* CAN driver for Geschwister Schneider USB/CAN devices
  * and bytewerk.org candleLight USB CAN interfaces.
  *
@@ -6,15 +7,6 @@
  * Copyright (C) 2016 Hubert Denkmair
  *
  * Many thanks to all socketcan devs!
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published
- * by the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  */
 
 #include <linux/init.h>
@@ -192,14 +184,16 @@
 
 	struct usb_anchor tx_submitted;
 	atomic_t active_tx_urbs;
+	void *rxbuf[GS_MAX_RX_URBS];
+	dma_addr_t rxbuf_dma[GS_MAX_RX_URBS];
 };
 
 /* usb interface struct */
 struct gs_usb {
 	struct gs_can *canch[GS_MAX_INTF];
 	struct usb_anchor rx_submitted;
-	atomic_t active_channels;
 	struct usb_device *udev;
+	u8 active_channels;
 };
 
 /* 'allocate' a tx context.
@@ -387,6 +381,9 @@
 	}
 
 	if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
+		stats->rx_over_errors++;
+		stats->rx_errors++;
+
 		skb = alloc_can_err_skb(netdev, &cf);
 		if (!skb)
 			goto resubmit_urb;
@@ -394,8 +391,6 @@
 		cf->can_id |= CAN_ERR_CRTL;
 		cf->can_dlc = CAN_ERR_DLC;
 		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
-		stats->rx_over_errors++;
-		stats->rx_errors++;
 		netif_rx(skb);
 	}
 
@@ -596,10 +591,11 @@
 	if (rc)
 		return rc;
 
-	if (atomic_add_return(1, &parent->active_channels) == 1) {
+	if (!parent->active_channels) {
 		for (i = 0; i < GS_MAX_RX_URBS; i++) {
 			struct urb *urb;
 			u8 *buf;
+			dma_addr_t buf_dma;
 
 			/* alloc rx urb */
 			urb = usb_alloc_urb(0, GFP_KERNEL);
@@ -610,13 +606,15 @@
 			buf = usb_alloc_coherent(dev->udev,
 						 sizeof(struct gs_host_frame),
 						 GFP_KERNEL,
-						 &urb->transfer_dma);
+						 &buf_dma);
 			if (!buf) {
 				netdev_err(netdev,
 					   "No memory left for USB buffer\n");
 				usb_free_urb(urb);
 				return -ENOMEM;
 			}
+
+			urb->transfer_dma = buf_dma;
 
 			/* fill, anchor, and submit rx urb */
 			usb_fill_bulk_urb(urb,
@@ -641,9 +639,16 @@
 					   rc);
 
 				usb_unanchor_urb(urb);
+				usb_free_coherent(dev->udev,
+						  sizeof(struct gs_host_frame),
+						  buf,
+						  buf_dma);
 				usb_free_urb(urb);
 				break;
 			}
+
+			dev->rxbuf[i] = buf;
+			dev->rxbuf_dma[i] = buf_dma;
 
 			/* Drop reference,
 			 * USB core will take care of freeing it
@@ -674,6 +679,7 @@
 		flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
 
 	/* finally start device */
+	dev->can.state = CAN_STATE_ERROR_ACTIVE;
 	dm->mode = cpu_to_le32(GS_CAN_MODE_START);
 	dm->flags = cpu_to_le32(flags);
 	rc = usb_control_msg(interface_to_usbdev(dev->iface),
@@ -690,13 +696,13 @@
 	if (rc < 0) {
 		netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
 		kfree(dm);
+		dev->can.state = CAN_STATE_STOPPED;
 		return rc;
 	}
 
 	kfree(dm);
 
-	dev->can.state = CAN_STATE_ERROR_ACTIVE;
-
+	parent->active_channels++;
 	if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 		netif_start_queue(netdev);
 
@@ -708,16 +714,26 @@
 	int rc;
 	struct gs_can *dev = netdev_priv(netdev);
 	struct gs_usb *parent = dev->parent;
+	unsigned int i;
 
 	netif_stop_queue(netdev);
 
 	/* Stop polling */
-	if (atomic_dec_and_test(&parent->active_channels))
+	parent->active_channels--;
+	if (!parent->active_channels) {
 		usb_kill_anchored_urbs(&parent->rx_submitted);
+		for (i = 0; i < GS_MAX_RX_URBS; i++)
+			usb_free_coherent(dev->udev,
+					  sizeof(struct gs_host_frame),
+					  dev->rxbuf[i],
+					  dev->rxbuf_dma[i]);
+	}
 
 	/* Stop sending URBs */
 	usb_kill_anchored_urbs(&dev->tx_submitted);
 	atomic_set(&dev->active_tx_urbs, 0);
+
+	dev->can.state = CAN_STATE_STOPPED;
 
 	/* reset the device */
 	rc = gs_cmd_reset(dev);
@@ -847,7 +863,7 @@
 
 	netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
 
-	/* dev settup */
+	/* dev setup */
 	strcpy(dev->bt_const.name, "gs_usb");
 	dev->bt_const.tseg1_min = le32_to_cpu(bt_const->tseg1_min);
 	dev->bt_const.tseg1_max = le32_to_cpu(bt_const->tseg1_max);
@@ -871,7 +887,7 @@
 		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
 	}
 
-	/* can settup */
+	/* can setup */
 	dev->can.state = CAN_STATE_STOPPED;
 	dev->can.clock.freq = le32_to_cpu(bt_const->fclk_can);
 	dev->can.bittiming_const = &dev->bt_const;
@@ -990,8 +1006,6 @@
 	}
 
 	init_usb_anchor(&dev->rx_submitted);
-
-	atomic_set(&dev->active_channels, 0);
 
 	usb_set_intfdata(intf, dev);
 	dev->udev = interface_to_usbdev(intf);

--
Gitblit v1.6.2