On 3-1-2017 18:59, Luis R. Rodriguez wrote: > On Mon, Dec 26, 2016 at 05:35:59PM +0100, Pavel Machek wrote: >> >> Right question is "should we solve it without user-space help"? >> >> Answer is no, too. Way too complex. Yes, it would be nice if hardware >> was designed in such a way that getting calibration data from kernel >> is easy, and if you design hardware, please design it like that. But >> N900 is not designed like that and getting the calibration through >> userspace looks like only reasonable solution. > > Arend seems to have a better alternative in mind possible for other > devices which *can* probably pull of doing this easily and nicely, > given the nasty history of the usermode helper crap we should not > in any way discourage such efforts. > > Arend -- please look at the firmware cache, it not a hash but a hash > table for an O(1) lookups would be a welcomed change, then it could > be repurposed for what you describe, I think the only difference is > you'd perhaps want a custom driver hook to fetch the calibration data > so the driver does whatever it needs. Hi Luis, I let my idea catch dust on the shelf for a while. Actually had a couple of patches ready, but did get around testing them. So I wanted to rebase them on your linux-next tree. I bumped into the umh lock thing and was wondering why direct filesystem access was under that lock as well. In your tree I noticed a fix for that. The more reason to base my work on top of your firmware_class changes. Now my question is what is the best branch to choose, because you have a "few" in that repo to choose from ;-) Regards, Arend
