On Sun, Apr 21, 2013 at 4:21 PM, Martin Sucha <[email protected]> wrote: > Hi, > > On 04/21/2013 03:52 PM, Ján Veselý wrote: >> There is no way for ps2 driver to know whether an interrupt event can >> be safely dropped, dropping one part of a message desync and breaks >> ps2 protocol, > I don't know how PS/2 protocol works, but I'm wondering, couldn't the > keyboard/mouse driver recover from the data drop if it knew it occured? > Like send a reset command to the device or something? (I know an > isdv4-based tablet device could be reset if necessary)
the mouse can be reset if we know there is a protocol error, the problem is detecting those errors. you can see the packet format here: http://www.computer-engineering.org/ps2mouse/ in the basic version there is only one bit hardset to 1, in the 3-button intellimouse version there is an addition of z-axis with limited range 5-button intellimouse version there are two more bits hardwired to 0, the rest are legal values. Basic checks on those values is possible but I don't think it would reliable, in general you'll need to check 'sanity' of mouse movements/clicks. Jan > > Martin Sucha > > > _______________________________________________ > HelenOS-devel mailing list > [email protected] > http://lists.modry.cz/cgi-bin/listinfo/helenos-devel _______________________________________________ HelenOS-devel mailing list [email protected] http://lists.modry.cz/cgi-bin/listinfo/helenos-devel
