4.19-stable review patch. If anyone has any objections, please let me know.
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From: Hardik Gajjar hgajjar@de.adit-jv.com
[ Upstream commit a04224da1f3424b2c607b12a3bd1f0e302fb8231 ]
Previously, gadget assignment to the net device occurred exclusively during the initial binding attempt.
Nevertheless, the gadget pointer could change during bind/unbind cycles due to various conditions, including the unloading/loading of the UDC device driver or the detachment/reconnection of an OTG-capable USB hub device.
This patch relocates the gether_set_gadget() function out from ncm_opts->bound condition check, ensuring that the correct gadget is assigned during each bind request.
The provided logs demonstrate the consistency of ncm_opts throughout the power cycle, while the gadget may change.
* OTG hub connected during boot up and assignment of gadget and ncm_opts pointer
[ 2.366301] usb 2-1.5: New USB device found, idVendor=2996, idProduct=0105 [ 2.366304] usb 2-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 2.366306] usb 2-1.5: Product: H2H Bridge [ 2.366308] usb 2-1.5: Manufacturer: Aptiv [ 2.366309] usb 2-1.5: SerialNumber: 13FEB2021 [ 2.427989] usb 2-1.5: New USB device found, VID=2996, PID=0105 [ 2.428959] dabridge 2-1.5:1.0: dabridge 2-4 total endpoints=5, 0000000093a8d681 [ 2.429710] dabridge 2-1.5:1.0: P(0105) D(22.06.22) F(17.3.16) H(1.1) high-speed [ 2.429714] dabridge 2-1.5:1.0: Hub 2-2 P(0151) V(06.87) [ 2.429956] dabridge 2-1.5:1.0: All downstream ports in host mode
[ 2.430093] gadget 000000003c414d59 ------> gadget pointer
* NCM opts and associated gadget pointer during First ncm_bind
[ 34.763929] NCM opts 00000000aa304ac9 [ 34.763930] NCM gadget 000000003c414d59
* OTG capable hub disconnecte or assume driver unload.
[ 97.203114] usb 2-1: USB disconnect, device number 2 [ 97.203118] usb 2-1.1: USB disconnect, device number 3 [ 97.209217] usb 2-1.5: USB disconnect, device number 4 [ 97.230990] dabr_udc deleted
* Reconnect the OTG hub or load driver assaign new gadget pointer.
[ 111.534035] usb 2-1.1: New USB device found, idVendor=2996, idProduct=0120, bcdDevice= 6.87 [ 111.534038] usb 2-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 111.534040] usb 2-1.1: Product: Vendor [ 111.534041] usb 2-1.1: Manufacturer: Aptiv [ 111.534042] usb 2-1.1: SerialNumber: Superior [ 111.535175] usb 2-1.1: New USB device found, VID=2996, PID=0120 [ 111.610995] usb 2-1.5: new high-speed USB device number 8 using xhci-hcd [ 111.630052] usb 2-1.5: New USB device found, idVendor=2996, idProduct=0105, bcdDevice=21.02 [ 111.630055] usb 2-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 111.630057] usb 2-1.5: Product: H2H Bridge [ 111.630058] usb 2-1.5: Manufacturer: Aptiv [ 111.630059] usb 2-1.5: SerialNumber: 13FEB2021 [ 111.687464] usb 2-1.5: New USB device found, VID=2996, PID=0105 [ 111.690375] dabridge 2-1.5:1.0: dabridge 2-8 total endpoints=5, 000000000d87c961 [ 111.691172] dabridge 2-1.5:1.0: P(0105) D(22.06.22) F(17.3.16) H(1.1) high-speed [ 111.691176] dabridge 2-1.5:1.0: Hub 2-6 P(0151) V(06.87) [ 111.691646] dabridge 2-1.5:1.0: All downstream ports in host mode
[ 111.692298] gadget 00000000dc72f7a9 --------> new gadget ptr on connect
* NCM opts and associated gadget pointer during second ncm_bind
[ 113.271786] NCM opts 00000000aa304ac9 -----> same opts ptr used during first bind [ 113.271788] NCM gadget 00000000dc72f7a9 ----> however new gaget ptr, that will not set in net_device due to ncm_opts->bound = true
Signed-off-by: Hardik Gajjar hgajjar@de.adit-jv.com Link: https://lore.kernel.org/r/20231020153324.82794-1-hgajjar@de.adit-jv.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/gadget/function/f_ncm.c | 27 +++++++++++---------------- 1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c index 8d23a870b7b7f..2ef2464a50432 100644 --- a/drivers/usb/gadget/function/f_ncm.c +++ b/drivers/usb/gadget/function/f_ncm.c @@ -1435,7 +1435,7 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) struct usb_composite_dev *cdev = c->cdev; struct f_ncm *ncm = func_to_ncm(f); struct usb_string *us; - int status; + int status = 0; struct usb_ep *ep; struct f_ncm_opts *ncm_opts;
@@ -1453,22 +1453,17 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) 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, - * in each configuration its functions are bound in sequence - * with list_for_each_entry, so we assume no race condition - * with regard to ncm_opts->bound access - */ - if (!ncm_opts->bound) { - mutex_lock(&ncm_opts->lock); - gether_set_gadget(ncm_opts->net, cdev->gadget); + mutex_lock(&ncm_opts->lock); + gether_set_gadget(ncm_opts->net, cdev->gadget); + if (!ncm_opts->bound) status = gether_register_netdev(ncm_opts->net); - mutex_unlock(&ncm_opts->lock); - if (status) - goto fail; - ncm_opts->bound = true; - } + mutex_unlock(&ncm_opts->lock); + + if (status) + goto fail; + + ncm_opts->bound = true; + us = usb_gstrings_attach(cdev, ncm_strings, ARRAY_SIZE(ncm_string_defs)); if (IS_ERR(us)) {