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path: root/drivers/net/can/usb
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Diffstat (limited to 'drivers/net/can/usb')
-rw-r--r--drivers/net/can/usb/etas_es58x/es58x_core.c9
-rw-r--r--drivers/net/can/usb/etas_es58x/es58x_core.h8
-rw-r--r--drivers/net/can/usb/gs_usb.c10
3 files changed, 15 insertions, 12 deletions
diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c
index 2ed2370a3166..2d73ebbf3836 100644
--- a/drivers/net/can/usb/etas_es58x/es58x_core.c
+++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
@@ -1787,7 +1787,7 @@ static int es58x_open(struct net_device *netdev)
struct es58x_device *es58x_dev = es58x_priv(netdev)->es58x_dev;
int ret;
- if (atomic_inc_return(&es58x_dev->opened_channel_cnt) == 1) {
+ if (!es58x_dev->opened_channel_cnt) {
ret = es58x_alloc_rx_urbs(es58x_dev);
if (ret)
return ret;
@@ -1805,12 +1805,13 @@ static int es58x_open(struct net_device *netdev)
if (ret)
goto free_urbs;
+ es58x_dev->opened_channel_cnt++;
netif_start_queue(netdev);
return ret;
free_urbs:
- if (atomic_dec_and_test(&es58x_dev->opened_channel_cnt))
+ if (!es58x_dev->opened_channel_cnt)
es58x_free_urbs(es58x_dev);
netdev_err(netdev, "%s: Could not open the network device: %pe\n",
__func__, ERR_PTR(ret));
@@ -1845,7 +1846,8 @@ static int es58x_stop(struct net_device *netdev)
es58x_flush_pending_tx_msg(netdev);
- if (atomic_dec_and_test(&es58x_dev->opened_channel_cnt))
+ es58x_dev->opened_channel_cnt--;
+ if (!es58x_dev->opened_channel_cnt)
es58x_free_urbs(es58x_dev);
return 0;
@@ -2215,7 +2217,6 @@ static struct es58x_device *es58x_init_es58x_dev(struct usb_interface *intf,
init_usb_anchor(&es58x_dev->tx_urbs_idle);
init_usb_anchor(&es58x_dev->tx_urbs_busy);
atomic_set(&es58x_dev->tx_urbs_idle_cnt, 0);
- atomic_set(&es58x_dev->opened_channel_cnt, 0);
usb_set_intfdata(intf, es58x_dev);
es58x_dev->rx_pipe = usb_rcvbulkpipe(es58x_dev->udev,
diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.h b/drivers/net/can/usb/etas_es58x/es58x_core.h
index 826a15871573..e5033cb5e695 100644
--- a/drivers/net/can/usb/etas_es58x/es58x_core.h
+++ b/drivers/net/can/usb/etas_es58x/es58x_core.h
@@ -373,8 +373,6 @@ struct es58x_operators {
* queue wake/stop logic should prevent this URB from getting
* empty. Please refer to es58x_get_tx_urb() for more details.
* @tx_urbs_idle_cnt: number of urbs in @tx_urbs_idle.
- * @opened_channel_cnt: number of channels opened (c.f. es58x_open()
- * and es58x_stop()).
* @ktime_req_ns: kernel timestamp when es58x_set_realtime_diff_ns()
* was called.
* @realtime_diff_ns: difference in nanoseconds between the clocks of
@@ -384,6 +382,10 @@ struct es58x_operators {
* in RX branches.
* @rx_max_packet_size: Maximum length of bulk-in URB.
* @num_can_ch: Number of CAN channel (i.e. number of elements of @netdev).
+ * @opened_channel_cnt: number of channels opened. Free of race
+ * conditions because its two users (net_device_ops:ndo_open()
+ * and net_device_ops:ndo_close()) guarantee that the network
+ * stack big kernel lock (a.k.a. rtnl_mutex) is being hold.
* @rx_cmd_buf_len: Length of @rx_cmd_buf.
* @rx_cmd_buf: The device might split the URB commands in an
* arbitrary amount of pieces. This buffer is used to concatenate
@@ -406,7 +408,6 @@ struct es58x_device {
struct usb_anchor tx_urbs_busy;
struct usb_anchor tx_urbs_idle;
atomic_t tx_urbs_idle_cnt;
- atomic_t opened_channel_cnt;
u64 ktime_req_ns;
s64 realtime_diff_ns;
@@ -415,6 +416,7 @@ struct es58x_device {
u16 rx_max_packet_size;
u8 num_can_ch;
+ u8 opened_channel_cnt;
u16 rx_cmd_buf_len;
union es58x_urb_cmd rx_cmd_buf;
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index b487e3fe770a..d35749fad1ef 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -191,8 +191,8 @@ struct gs_can {
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.
@@ -589,7 +589,7 @@ static int gs_can_open(struct net_device *netdev)
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;
@@ -690,6 +690,7 @@ static int gs_can_open(struct net_device *netdev)
dev->can.state = CAN_STATE_ERROR_ACTIVE;
+ parent->active_channels++;
if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
netif_start_queue(netdev);
@@ -705,7 +706,8 @@ static int gs_can_close(struct net_device *netdev)
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);
/* Stop sending URBs */
@@ -984,8 +986,6 @@ static int gs_usb_probe(struct usb_interface *intf,
init_usb_anchor(&dev->rx_submitted);
- atomic_set(&dev->active_channels, 0);
-
usb_set_intfdata(intf, dev);
dev->udev = interface_to_usbdev(intf);