Return-Path: Date: Mon, 21 Feb 2011 13:50:40 +0100 (CET) From: Jiri Kosina To: Alan Ott Cc: Antonio Ospite , linux-input@vger.kernel.org, linux-bluetooth@vger.kernel.org, Marcel Holtmann , "Gustavo F. Padovan" , Bastien Nocera , Jim Paris , "pascal@pabr.org" Subject: Re: [PATCH 2/2] bt hidp: send Output reports using SET_REPORT on the Control channel In-Reply-To: <4D61DFE0.5020400@signal11.us> Message-ID: References: <1298222806-19433-1-git-send-email-ospite@studenti.unina.it> <1298222806-19433-3-git-send-email-ospite@studenti.unina.it> <4D61DFE0.5020400@signal11.us> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-ID: On Sun, 20 Feb 2011, Alan Ott wrote: > On 02/20/2011 12:26 PM, Antonio Ospite wrote: > > The current implementation of hidp_output_raw_report() relies only on > > the Control channel even for Output reports, and the BT HID > > specification [1] does not mention using the DATA message for Output > > reports on the Control channel (see section 7.9.1 and also Figure 11: > > SET_ Flow Chart), so let us just use SET_REPORT. > > > > This also fixes sending Output reports to some devices (like Sony > > Sixaxis) which are not able to handle DATA messages on the Control > > channel. > > > > Ideally hidp_output_raw_report() could be improved to use this scheme: > > Feature Report -- SET_REPORT on the Control channel > > Output Report -- DATA on the Interrupt channel > > for more efficiency, but as said above, right now only the Control > > channel is used. > > > > [1] http://www.bluetooth.com/Specification%20Documents/HID_SPEC_V10.pdf > > > > case HID_OUTPUT_REPORT: > > - report_type = HIDP_TRANS_DATA | HIDP_DATA_RTYPE_OUPUT; > > + report_type = HIDP_TRANS_SET_REPORT | HIDP_DATA_RTYPE_OUPUT; > > > > I think this is right. Section 7.4[.0] says that SET_ and GET_ requests return > with HANDSHAKE. Section 7.4.9 says that DATA does _not_ return a HANDSHAKE. My > patch to hidp_output_raw_report() relies on getting a HANDSHAKE back, so it > wouldn't have worked with BT devices that take output reports. Since I don't > have any that do, I couldn't test it. (And it was like that when I got here :) > ) > > For the whole set: > Acked-by: Alan Ott Agreed. As an author of the original code, I agree with the change. But as it is in net/bluetooth, I'd at least have Acked-by from some of the Bluetooth folks before I take it through my tree. Marcel? Gustavo? Thanks, -- Jiri Kosina SUSE Labs, Novell Inc.