Hi Jaikumar, On Tue, May 24, 2011 at 7:44 PM, Jaikumar Ganesh <jaikumar@xxxxxxxxxx> wrote: > Hi Luiz, Ville: > > On Tue, May 24, 2011 at 9:20 AM, Luiz Augusto von Dentz > <luiz.dentz@xxxxxxxxx> wrote: >> >> Hi Jaikumar, >> >> On Tue, May 24, 2011 at 11:37 AM, Ville Tervo <ville.tervo@xxxxxxxxx> wrote: >> > Hi Jaikumar, >> > >> > On Mon, May 23, 2011 at 06:06:04PM -0700, ext Jaikumar Ganesh wrote: >> >> Add BT_POWER socket option used to control the power >> >> characteristics of the underlying ACL link. When the remote end >> >> has put the link in sniff mode and the host stack wants to send >> >> data we need need to explicitly exit sniff mode to work well with >> >> certain devices (For example, A2DP on Plantronics Voyager 855). >> >> However, this causes problems with HID devices. >> >> >> >> Hence, moving into active mode when sending data, irrespective >> >> of who set the sniff mode has been made as a socket option. By >> >> default, we will move into active mode. HID devices can set the >> >> L2CAP socket option to prevent this from happening. >> >> >> > >> > I would prefer keeping old way the default way. Otherwise you need to update >> > all socket users in user space. Other that that this looks good to me. >> >> What is wrong that we need such control to be done in userspace? > > I don't think my emails reached the list so sending it again. > > Ville: > Its the other way round. With this approach and the default value, > only the HID > userspace socket needs to be modified - nothing else. > > Luiz: > The HID devices can send data even when in sniff mode and hence we > need to change the userspace > L2CAP socket option. While sending data without exiting sniff mode for > A2DP for example, causes problems > as explained in the commit message. Now I get it, we should definitely fix it for a2dp/hfp, but still introducing new socket options it is a quite dangerous game, I wonder how much power do we really save in case of HID and at what cost since it probably add latency to input devices while on sniff mode. -- Luiz Augusto von Dentz Computer Engineer -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
