diff options
| author | Krzysztof Opasiak <k.opasiak@samsung.com> | 2016-12-20 19:52:16 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-12 11:39:11 +0100 |
| commit | 2b95c939cb88c3182e9dd681d4cf40b70985b8a5 (patch) | |
| tree | 65ff0b943ec3f2f7fe6bbcce4cbd7152e8404856 /drivers/usb/gadget/composite.c | |
| parent | 735daeec9e6062cad8aab412d0c04d26ae8e13e7 (diff) | |
usb: gadget: composite: Test get_alt() presence instead of set_alt()
commit 7e4da3fcf7c9fe042f2f7cb7bf23861a899b4a8f upstream.
By convention (according to doc) if function does not provide
get_alt() callback composite framework should assume that it has only
altsetting 0 and should respond with error if host tries to set
other one.
After commit dd4dff8b035f ("USB: composite: Fix bug: should test
set_alt function pointer before use it")
we started checking set_alt() callback instead of get_alt().
This check is useless as we check if set_alt() is set inside
usb_add_function() and fail if it's NULL.
Let's fix this check and move comment about why we check the get
method instead of set a little bit closer to prevent future false
fixes.
Fixes: dd4dff8b035f ("USB: composite: Fix bug: should test set_alt function pointer before use it")
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/gadget/composite.c')
| -rw-r--r-- | drivers/usb/gadget/composite.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c index e38b21087d26..e1841fa96412 100644 --- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -1694,9 +1694,7 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) value = min(w_length, (u16) 1); break; - /* function drivers must handle get/set altsetting; if there's - * no get() method, we know only altsetting zero works. - */ + /* function drivers must handle get/set altsetting */ case USB_REQ_SET_INTERFACE: if (ctrl->bRequestType != USB_RECIP_INTERFACE) goto unknown; @@ -1705,7 +1703,13 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) f = cdev->config->interface[intf]; if (!f) break; - if (w_value && !f->set_alt) + + /* + * If there's no get_alt() method, we know only altsetting zero + * works. There is no need to check if set_alt() is not NULL + * as we check this in usb_add_function(). + */ + if (w_value && !f->get_alt) break; value = f->set_alt(f, w_index, w_value); if (value == USB_GADGET_DELAYED_STATUS) { |