On Thu, Jul 01, 2021 at 03:03:12PM -0500, Ian Pilcher wrote: > On 7/1/21 12:59 PM, Greg KH wrote: > > Oh that's horrible, please no, do not do that :) > > Indeed it is, but it works, and it meets my main objective, which is to > allow the use of distribution kernel packages and modules. > > > How about a third option, the correct one: > > - submit your code changes upstream and they get merged into the > > main kernel tree and no monkeypatching is ever needed at all! > > > > Have you submitted your changes upstream to the existing drivers? What > > is preventing that from happening today? > > There are a couple of reasons that I've never attempted to do this. > > * Scope of work - Currently, there is simply no mechanism to call an LED > trigger from the ahci or libahci modules, presumably because this is > something that really ought to be done by the hardware. So I would > have to add some sort of generic framework to associate LED triggers > with AHCI ports. > > I probably also don't really have the knowledge to do this. I am not > familiar with locking, memory management, etc. in the kernel. Just > because my "hack" works on a specific 2-core NAS doesn't mean that it > won't cause all sorts of breakage on a higher-performance system with > more parallelism. Why are ahci devices somehow "special" here? Just add a trigger to the ahci core for LEDs and all should "just work". We've done that for many subsystems already. > * (Probable) lack of upstream interest - As I mentioned, disk activity > LEDs really ought to be handled by the hardware. I don't know of any > other system that suffers from this particular limitation. So this > is a very, very niche use case. (Most users of this hardware use the > manufacturer's "firmware".) Are you sure we don't already have LED triggers for disk activity? Have you tried the ledtrig-disk.c driver? It says it works on ATA devices, no reason it can't also work for other device types. > I did ask about this on the linux-ide mailing list long ago when I > first wrote the modules, but I don't think that I ever received a > response, which reinforces my belief that upstream isn't likely to be > receptive. > > I've invested significant time in kernel patches in the past, only to > see them ultimately not be accepted, so I would need to know that > upstream was truly interested in such a feature before I would consider > making such a commitment. That's not fair, there is no way anyone can promise anyone that their patches will be accepted, _before_ anyone sees them. What would _you_ do if you were in the kernel maintainer's position and read something like this? good luck! greg k-h
