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author | Andrzej Pietrasiewicz <andrzej.p@samsung.com> | 2013-08-08 07:43:28 (GMT) |
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committer | Felipe Balbi <balbi@ti.com> | 2013-08-27 19:06:08 (GMT) |
commit | 5a68e9b57b1c1984dae8a9625bbf1a505d166035 (patch) | |
tree | ce6ef1222336cbab1632701bce216f7cf4c41c93 /drivers/usb/gadget/configfs.c | |
parent | 154547c4fe0fbe92185e69a6cdc2b0502b361995 (diff) | |
download | linux-5a68e9b57b1c1984dae8a9625bbf1a505d166035.tar.xz |
usb: gadget: configfs: keep a function if it is not successfully added
If usb_add_function() fails then the currently processed function
is already not in the list in struct config_usb_cfg, and neither is it
in the list in struct usb_configuration. At the err_purge_funcs label the
purge_config_funcs() is called, which iterates over all configurations,
and in each configuration it iterates over all _successfully_ added
functions, and moves them back from the list in struct usb_configuration
to the list in struct config_usb_cfg. BUT the function which has just
failed adding and caused the unwind process is not taken care of and
is effectively lost.
This patch modifies the configfs_composite_bind() function so that if
the usb_add_function() fails, then the currently processed function
is returned to the list in struct config_usb_cfg.
It would be tempting to delay the list_del() in question after
usb_add_function() invocation, but a struct list_head (&f->list) cannot be
stored in more than one list at the same time, so the list_del() must
be called before usb_add_function(). Hence, the solution is to list_add()
after usb_add_function() in case of error.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers/usb/gadget/configfs.c')
-rw-r--r-- | drivers/usb/gadget/configfs.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c index 80e7f75..8f0d614 100644 --- a/drivers/usb/gadget/configfs.c +++ b/drivers/usb/gadget/configfs.c @@ -859,8 +859,10 @@ static int configfs_composite_bind(struct usb_gadget *gadget, list_for_each_entry_safe(f, tmp, &cfg->func_list, list) { list_del(&f->list); ret = usb_add_function(c, f); - if (ret) + if (ret) { + list_add(&f->list, &cfg->func_list); goto err_purge_funcs; + } } usb_ep_autoconfig_reset(cdev->gadget); } |