From: Hardik Gajjar <hgajjar@xxxxxxxxxxxxxx>
[ 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@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231020153324.82794-1-hgajjar@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 00aea45a04e95..d42cd1d036bdf 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)) {
--
2.42.0
