On Thu, Oct 04, 2012 at 06:30:11PM +0200, Jean Delvare wrote: > Hi Andrew, > > On Thu, 4 Oct 2012 11:30:45 -0400, Andrew Potter wrote: > > Hi, I wasn't quite sure from the information on lm-sensors.org how to open > > an official ticket, but the details of my problem are here: > > > > https://bbs.archlinux.org/viewtopic.php?pid=1170583 > > > > Basically, when I probe i915 gmbus panel (i2c-2) with sensors-detect, when > > it probes address 0x4f my monitor settings (I think the sharpness mostly) > > are changed drastically. This is persistent over any operating system and > > reboot, leading me to believe a) its a hardware issue, or b) nothing > > usually touches whatever values were changed. Any help would be greatly > > appreciated, in the forum post I've also included some experimentation with > > i2c-tools. The problem originally occured on an Arch Linux system. Let me > > know if you need anything else! > > Thanks for reporting. We have had that kind of problem popping up every > other year or so, and take such reports very seriously. We've done our > best to make sensors-detect as safe as possible, but the fact is, the > I2C and SMBus protocols do not support device probing in general, so > the whole thing is a hack, and hacks can turn bad sometimes. > > Please keep in mind that everything you will do to investigate and > solve this issue (including things I or others may suggest you do) may > make things even worse than they are today. So it's all up to you what > you want to do and when you prefer to stop and stick with what you have. > > First thing I would like to know is the version of lm-sensors (or > sensors-detect) you have been running. > > Second thing I would like to know is the exact revision of your laptop > HP Pavillon DV7. If possible, provide the dmidecode output. We want to > document the problem and prevent it from happening to other users with > the same hardware, using a blacklist if needed. > > One thing I don't quite understand is how there can be two different > graphics chips (one Intel, one Nvidia) in a laptop. What sense does it > make, and which one are you using? If the Intel is an integrated thing > and the Nvidia chip was added and is supposed to be better, then I > would suppose that's what you're using, but then I do not understand > how messing up with the Intel I2C buses can have any adverse effect. > I think I know the answer to that one: the laptop uses the Intel CPU graphics for most applications to consserve power, but can switch to the Nvidia chip for high-demand graphics applications such as games. Guenter _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
