can: gs_usb: gs_can_open(): improve error handling

The gs_usb driver handles USB devices with more than 1 CAN channel.
The RX path for all channels share the same bulk endpoint (the
transmitted bulk data encodes the channel number). These per-device
resources are allocated and submitted by the first opened channel.

During this allocation, the resources are either released immediately
in case of a failure or the URBs are anchored. All anchored URBs are
finally killed with gs_usb_disconnect().

Currently, gs_can_open() returns with an error if the allocation of a
URB or a buffer fails. However, if usb_submit_urb() fails, the driver
continues with the URBs submitted so far, even if no URBs were
successfully submitted.

Treat every error as fatal and free all allocated resources
immediately.

Switch to goto-style error handling, to prepare the driver for more
per-device resource allocation.

Cc: stable@vger.kernel.org
Cc: John Whittington <git@jbrengineering.co.uk>
Link: https://lore.kernel.org/all/20230716-gs_usb-fix-time-stamp-counter-v1-1-9017cefcd9d5@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Marc Kleine-Budde 2023-07-07 13:43:10 +02:00
parent 0dd1805fe4
commit 2603be9e81

View file

@ -833,6 +833,7 @@ static int gs_can_open(struct net_device *netdev)
.mode = cpu_to_le32(GS_CAN_MODE_START),
};
struct gs_host_frame *hf;
struct urb *urb = NULL;
u32 ctrlmode;
u32 flags = 0;
int rc, i;
@ -856,13 +857,14 @@ static int gs_can_open(struct net_device *netdev)
if (!parent->active_channels) {
for (i = 0; i < GS_MAX_RX_URBS; i++) {
struct urb *urb;
u8 *buf;
/* alloc rx urb */
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb)
return -ENOMEM;
if (!urb) {
rc = -ENOMEM;
goto out_usb_kill_anchored_urbs;
}
/* alloc rx buffer */
buf = kmalloc(dev->parent->hf_size_rx,
@ -870,8 +872,8 @@ static int gs_can_open(struct net_device *netdev)
if (!buf) {
netdev_err(netdev,
"No memory left for USB buffer\n");
usb_free_urb(urb);
return -ENOMEM;
rc = -ENOMEM;
goto out_usb_free_urb;
}
/* fill, anchor, and submit rx urb */
@ -894,9 +896,7 @@ static int gs_can_open(struct net_device *netdev)
netdev_err(netdev,
"usb_submit failed (err=%d)\n", rc);
usb_unanchor_urb(urb);
usb_free_urb(urb);
break;
goto out_usb_unanchor_urb;
}
/* Drop reference,
@ -945,7 +945,8 @@ static int gs_can_open(struct net_device *netdev)
if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
gs_usb_timestamp_stop(dev);
dev->can.state = CAN_STATE_STOPPED;
return rc;
goto out_usb_kill_anchored_urbs;
}
parent->active_channels++;
@ -953,6 +954,18 @@ static int gs_can_open(struct net_device *netdev)
netif_start_queue(netdev);
return 0;
out_usb_unanchor_urb:
usb_unanchor_urb(urb);
out_usb_free_urb:
usb_free_urb(urb);
out_usb_kill_anchored_urbs:
if (!parent->active_channels)
usb_kill_anchored_urbs(&dev->tx_submitted);
close_candev(netdev);
return rc;
}
static int gs_usb_get_state(const struct net_device *netdev,