On Fri, Feb 20, 2015 at 4:21 PM, Mario Limonciello <mario_limonciello@xxxxxxxx> wrote: > > On 02/20/2015 02:41 PM, Pali Rohár wrote: >> [snipped] > >> There is problem with some synaptics touchpad on some laptops >> (probably not dell). Windows driver loads own firmware into >> synaptics touchpad which use different protocol (as original >> firmware in touchpad). And that loaded firmware is active until >> laptop is not shut down. When you reboot from Windows to Linux >> then linux kernel driver refuse to identify & use touchpad >> because it does not support that new firmware loaded by >> Windows... I do not know lot of about this problem, I just heard >> about it from other people. I did not see any laptop "in action". >> > Ah, so it's a special interface that's implemented in the Synaptics Windows > driver. As described above this sounds like a stop gap type solution to > resolve a field problem until the firmware can be implemented into > manufactured parts. I'd suspect that people who purchased the same model of > this computer later might run into problems without warm booting as the > firmware got updated into the manufacturer's factory. > > What is most likely happening is that the synaptics driver switches the touchpad into the i2c/hid protocol. And yes Synaptics told us that only a reset re-enables the touchpad in the PS/2 mode. Kernels 3.11 and later know how to deal with this mode (through hid-rmi), so we should not see these problems in the future unless hid-rmi is not compiled in the running kernel. Fortunately, we can deal with the Dell/Synaptics touchpads, the Lenovo ones are using SMBus, and we have never been able to talk to the devices with SMBus :( Cheers, Benjamin -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
