From: Oliver Neukum Date: Thu, 12 Mar 2026 08:45:32 +0000 (+0100) Subject: net: usb: cdc-ether: unify error handling in probe X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a99f06e579a39be6113d37e84658a20b71c52e5f;p=thirdparty%2Flinux.git 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 Link: https://patch.msgid.link/20260312084612.1469853-1-oneukum@suse.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c index a032c1ded4063..a0a5740590b94 100644 --- a/drivers/net/usb/cdc_ether.c +++ b/drivers/net/usb/cdc_ether.c @@ -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);