From: Romain Izard romain.izard.pro@gmail.com
To be able to use the default USB class drivers available in Microsoft Windows, we need to add OS descriptors to the exported USB gadget to tell the OS that we are compatible with the built-in drivers.
Copy the OS descriptor support from f_rndis into f_ncm. As a result, using the WINNCM compatible ID, the UsbNcm driver is loaded on enumeration without the need for a custom driver or inf file.
Signed-off-by: Romain Izard romain.izard.pro@gmail.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Joakim Tjernlund joakim.tjernlund@infinera.com Cc: stable@vger.kernel.org # v4.19 ---
Seems to have been forgotten when backporting NCM fixes. Needed to make Win10 accept Linux NCM gadget ethernet
drivers/usb/gadget/function/f_ncm.c | 47 +++++++++++++++++++++++++++-- drivers/usb/gadget/function/u_ncm.h | 3 ++ 2 files changed, 47 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c index e4aa370e86a9..b4571633f7b5 100644 --- a/drivers/usb/gadget/function/f_ncm.c +++ b/drivers/usb/gadget/function/f_ncm.c @@ -23,6 +23,7 @@ #include "u_ether.h" #include "u_ether_configfs.h" #include "u_ncm.h" +#include "configfs.h"
/* * This function is a "CDC Network Control Model" (CDC NCM) Ethernet link. @@ -1432,6 +1433,16 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) return -EINVAL;
ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst); + + if (cdev->use_os_string) { + f->os_desc_table = kzalloc(sizeof(*f->os_desc_table), + GFP_KERNEL); + if (!f->os_desc_table) + return -ENOMEM; + f->os_desc_n = 1; + f->os_desc_table[0].os_desc = &ncm_opts->ncm_os_desc; + } + /* * in drivers/usb/gadget/configfs.c:configfs_composite_bind() * configurations are bound in sequence with list_for_each_entry, @@ -1445,13 +1456,15 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) status = gether_register_netdev(ncm_opts->net); mutex_unlock(&ncm_opts->lock); if (status) - return status; + goto fail; ncm_opts->bound = true; } us = usb_gstrings_attach(cdev, ncm_strings, ARRAY_SIZE(ncm_string_defs)); - if (IS_ERR(us)) - return PTR_ERR(us); + if (IS_ERR(us)) { + status = PTR_ERR(us); + goto fail; + } ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id; ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id; ncm_data_intf.iInterface = us[STRING_DATA_IDX].id; @@ -1468,6 +1481,10 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) ncm_control_intf.bInterfaceNumber = status; ncm_union_desc.bMasterInterface0 = status;
+ if (cdev->use_os_string) + f->os_desc_table[0].if_id = + ncm_iad_desc.bFirstInterface; + status = usb_interface_id(c, f); if (status < 0) goto fail; @@ -1547,6 +1564,9 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) return 0;
fail: + kfree(f->os_desc_table); + f->os_desc_n = 0; + if (ncm->notify_req) { kfree(ncm->notify_req->buf); usb_ep_free_request(ncm->notify, ncm->notify_req); @@ -1601,16 +1621,22 @@ static void ncm_free_inst(struct usb_function_instance *f) gether_cleanup(netdev_priv(opts->net)); else free_netdev(opts->net); + kfree(opts->ncm_interf_group); kfree(opts); }
static struct usb_function_instance *ncm_alloc_inst(void) { struct f_ncm_opts *opts; + struct usb_os_desc *descs[1]; + char *names[1]; + struct config_group *ncm_interf_group;
opts = kzalloc(sizeof(*opts), GFP_KERNEL); if (!opts) return ERR_PTR(-ENOMEM); + opts->ncm_os_desc.ext_compat_id = opts->ncm_ext_compat_id; + mutex_init(&opts->lock); opts->func_inst.free_func_inst = ncm_free_inst; opts->net = gether_setup_default(); @@ -1619,8 +1645,20 @@ static struct usb_function_instance *ncm_alloc_inst(void) kfree(opts); return ERR_CAST(net); } + INIT_LIST_HEAD(&opts->ncm_os_desc.ext_prop); + + descs[0] = &opts->ncm_os_desc; + names[0] = "ncm";
config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type); + ncm_interf_group = + usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs, + names, THIS_MODULE); + if (IS_ERR(ncm_interf_group)) { + ncm_free_inst(&opts->func_inst); + return ERR_CAST(ncm_interf_group); + } + opts->ncm_interf_group = ncm_interf_group;
return &opts->func_inst; } @@ -1646,6 +1684,9 @@ static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
hrtimer_cancel(&ncm->task_timer);
+ kfree(f->os_desc_table); + f->os_desc_n = 0; + ncm_string_defs[0].id = 0; usb_free_all_descriptors(f);
diff --git a/drivers/usb/gadget/function/u_ncm.h b/drivers/usb/gadget/function/u_ncm.h index 67324f983343..dfd75ad61b3f 100644 --- a/drivers/usb/gadget/function/u_ncm.h +++ b/drivers/usb/gadget/function/u_ncm.h @@ -20,6 +20,9 @@ struct f_ncm_opts { struct net_device *net; bool bound;
+ struct config_group *ncm_interf_group; + struct usb_os_desc ncm_os_desc; + char ncm_ext_compat_id[16]; /* * Read/write access to configfs attributes is handled by configfs. *