On Tue, 19 Jul 2005 23:40:18 -0400 Stephen Evanchik wrote: > I have been receiving a lot of complaints that TrackPoints on > Synaptics pass-thru ports stopped working with 2.6.12. I retested > 2.6.9 and 2.6.11-rc3 successfully, I believe 2.6.11.7 may also work > but that is unconfirmed at this point. > > The behavior is always the same .. after sending the read secondary ID > command, the TrackPoint seems to be disabled from that point forward. > > Any ideas? Looks like this problem was introduced by the change from PSMOUSE_PS2 to PSMOUSE_TRACKPOINT in the TrackPoint support patch. The Synaptics driver needs to know whether the device on the pass-thru port is using 3-byte or 4-byte packets; however, instead of checking child->pktsize, it checks child->type >= PSMOUSE_GENPS - and this check is now giving a wrong result. Therefore the Synaptics driver configures the pass-thru port for 4-byte packets, and all 3-byte packets from TrackPoint seem to be thrown away. The patch below is reported to fix the problem - now the 4-byte mode is used only if child->pktsize == 4. Another option is to change the PSMOUSE_TRACKPOINT value so that it is less than PSMOUSE_GENPS, however, I think that checking child->pktsize is more correct in this case. In theory, someone could attach a device which uses 6-byte packets to the Synaptics pass-thru port; I'm not sure what would happen in this case, but with Synaptics confugured for 3-byte packets (as the patch below will do) this configuration even has a chance of working. --- Subject: [PATCH] Fix pass-thru port configuration in the Synaptics driver The Synaptics driver uses child->type to select either 3-byte or 4-byte packet size for the pass-thru port; this gives wrong results at least for PSMOUSE_TRACKPOINT. Change the check to use child->pktsize instead. Signed-off-by: Sergey Vlasov <[email protected]> --- linux-2.6.12/drivers/input/mouse/synaptics.c.alt-synaptics-with-trackpoint 2005-06-17 23:48:29 +0400 +++ linux-2.6.12/drivers/input/mouse/synaptics.c 2005-07-09 21:09:01 +0400 @@ -219,7 +219,7 @@ static void synaptics_pass_pt_packet(str serio_interrupt(ptport, packet[1], 0, NULL); serio_interrupt(ptport, packet[4], 0, NULL); serio_interrupt(ptport, packet[5], 0, NULL); - if (child->type >= PSMOUSE_GENPS) + if (child->pktsize == 4) serio_interrupt(ptport, packet[2], 0, NULL); } else serio_interrupt(ptport, packet[1], 0, NULL); @@ -233,7 +233,7 @@ static void synaptics_pt_activate(struct /* adjust the touchpad to child's choice of protocol */ if (child) { - if (child->type >= PSMOUSE_GENPS) + if (child->pktsize == 4) priv->mode |= SYN_BIT_FOUR_BYTE_CLIENT; else priv->mode &= ~SYN_BIT_FOUR_BYTE_CLIENT;
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