On Tue, 21 Sep 2010, Alan Ott wrote:
> Feature reports should only be sent on the control endpoint.
>
> The USB HID standard is unclear and confusing on this issue. It seems to
> suggest that Feature reports can be sent on a HID device's Interrupt OUT
> endpoint. This cannot be the case because the report type is not encoded in
> transfers sent out the Interrput OUT endpoint. If Feature reports were sent
> on the Interrupt OUT endpint, they would be indistinguishable from Output
> reports in the case where Report IDs were not used.
>
> Further, Windows and Mac OS X do not send Feature reports out the interrupt
> OUT Endpoint. They will only go out the Control Endpoint.
>
> In addition, many devices simply do not hande Feature reports sent out the Interrupt OUT endpoint.
>
> Reported-by: simon@xxxxxxxxxxxxx
> Signed-off-by: Alan Ott <alan@xxxxxxxxxxx>
> ---
> drivers/hid/usbhid/hid-core.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
> index b729c02..b0ccc42 100644
> --- a/drivers/hid/usbhid/hid-core.c
> +++ b/drivers/hid/usbhid/hid-core.c
> @@ -807,7 +807,7 @@ static int usbhid_output_raw_report(struct hid_device *hid, __u8 *buf, size_t co
> struct usb_host_interface *interface = intf->cur_altsetting;
> int ret;
>
> - if (usbhid->urbout) {
> + if (usbhid->urbout && report_type != HID_FEATURE_REPORT) {
> int actual_length;
> int skipped_report_id = 0;
> if (buf[0] == 0x0) {
Applied to the 'logitech' branch (as Simon's new Logitech driver is
depending on this).
--
Jiri Kosina
SUSE Labs, Novell Inc.
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