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net: usb: cdc-ether: unify error handling in probe 

usbnet_generic_cdc_bind() is duplicating the error handling
multiple times. That is bad. Unify it with jumps.

V2: Update error logging with every cause a unique message

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://patch.msgid.link/20260312084612.1469853-1-oneukum@suse.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
master
Oliver Neukum 2026-03-12 09:45:32 +01:00 committed by Jakub Kicinski
parent b87249aab4
commit a99f06e579
1 changed files with 30 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
drivers/net/usb/cdc_ether.c
View File

@ -115,7 +115,7 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
int len = intf->cur_altsetting->extralen;
struct usb_interface_descriptor *d;
struct cdc_state *info = (void *) &dev->data;
int status;
int status = -ENODEV;
int rndis;
bool android_rndis_quirk = false;
struct usb_driver *driver = driver_of(intf);
@ -169,10 +169,13 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
info->header = header.usb_cdc_header_desc;
info->ether = header.usb_cdc_ether_desc;
if (!info->u) {
if (rndis)
if (rndis) {
goto skip;
else /* in that case a quirk is mandatory */
} else {
/* in that case a quirk is mandatory */
dev_err(&dev->udev->dev, "No union descriptors\n");
goto bad_desc;
}
}
/* we need a master/control interface (what we're
* probed with) and a slave/data interface; union
@ -192,18 +195,20 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
android_rndis_quirk = true;
goto skip;
}
dev_err(&intf->dev, "bad CDC descriptors\n");
goto bad_desc;
}
if (info->control != intf) {
dev_dbg(&intf->dev, "bogus CDC Union\n");
/* Ambit USB Cable Modem (and maybe others)
* interchanges master and slave interface.
*/
if (info->data == intf) {
info->data = info->control;
info->control = intf;
} else
} else {
dev_err(&intf->dev, "bogus CDC Union\n");
goto bad_desc;
}
}
/* some devices merge these - skip class check */
@ -213,7 +218,7 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
/* a data interface altsetting does the real i/o */
d = &info->data->cur_altsetting->desc;
if (d->bInterfaceClass != USB_CLASS_CDC_DATA) {
dev_dbg(&intf->dev, "slave class %u\n", d->bInterfaceClass);
dev_err(&intf->dev, "slave class %u\n", d->bInterfaceClass);
goto bad_desc;
}
skip:
@ -227,7 +232,7 @@ skip:
if (rndis && is_rndis(&intf->cur_altsetting->desc) &&
header.usb_cdc_acm_descriptor &&
header.usb_cdc_acm_descriptor->bmCapabilities) {
dev_dbg(&intf->dev,
dev_err(&intf->dev,
"ACM capabilities %02x, not really RNDIS?\n",
header.usb_cdc_acm_descriptor->bmCapabilities);
goto bad_desc;
@ -242,14 +247,14 @@ skip:
if (header.usb_cdc_mdlm_desc &&
memcmp(header.usb_cdc_mdlm_desc->bGUID, mbm_guid, 16)) {
dev_dbg(&intf->dev, "GUID doesn't match\n");
dev_err(&intf->dev, "GUID doesn't match\n");
goto bad_desc;
}
if (header.usb_cdc_mdlm_detail_desc &&
header.usb_cdc_mdlm_detail_desc->bLength <
(sizeof(struct usb_cdc_mdlm_detail_desc) + 1)) {
dev_dbg(&intf->dev, "Descriptor too short\n");
dev_err(&intf->dev, "Descriptor too short\n");
goto bad_desc;
}
@ -267,7 +272,7 @@ skip:
info->control = usb_ifnum_to_if(dev->udev, 0);
info->data = usb_ifnum_to_if(dev->udev, 1);
if (!info->control || !info->data || info->control != intf) {
dev_dbg(&intf->dev,
dev_err(&intf->dev,
"rndis: master #0/%p slave #1/%p\n",
info->control,
info->data);
@ -275,7 +280,7 @@ skip:
}
} else if (!info->header || (!rndis && !info->ether)) {
dev_dbg(&intf->dev, "missing cdc %s%s%sdescriptor\n",
dev_err(&intf->dev, "missing cdc %s%s%sdescriptor\n",
info->header ? "" : "header ",
info->u ? "" : "union ",
info->ether ? "" : "ether ");
@ -287,16 +292,15 @@ skip:
*/
if (info->data != info->control) {
status = usb_driver_claim_interface(driver, info->data, dev);
if (status < 0)
return status;
if (status < 0) {
dev_err(&intf->dev, "Second interface unclaimable\n");
goto bad_desc;
}
}
status = usbnet_get_endpoints(dev, info->data);
if (status < 0) {
/* ensure immediate exit from usbnet_disconnect */
usb_set_intfdata(info->data, NULL);
if (info->data != info->control)
usb_driver_release_interface(driver, info->data);
return status;
dev_dbg(&intf->dev, "Mandatory endpoints missing\n");
goto bail_out_and_release;
}
/* status endpoint: optional for CDC Ethernet, not RNDIS (or ACM) */
@ -316,10 +320,9 @@ skip:
}
}
if (rndis && !dev->status) {
dev_dbg(&intf->dev, "missing RNDIS status endpoint\n");
usb_set_intfdata(info->data, NULL);
usb_driver_release_interface(driver, info->data);
return -ENODEV;
dev_err(&intf->dev, "missing RNDIS status endpoint\n");
status = -ENODEV;
goto bail_out_and_release;
}
/* override ethtool_ops */
@ -327,9 +330,12 @@ skip:
return 0;
bail_out_and_release:
usb_set_intfdata(info->data, NULL);
if (info->data != info->control)
usb_driver_release_interface(driver, info->data);
bad_desc:
dev_info(&dev->udev->dev, "bad CDC descriptors\n");
return -ENODEV;
return status;
}
EXPORT_SYMBOL_GPL(usbnet_generic_cdc_bind);