Arend Van Spriel <arend.vanspriel@xxxxxxxxxxxx> writes: > On 18-12-2016 13:09, Pali Rohár wrote: > >> File wl1251-nvs.bin is provided by linux-firmware package and contains >> default data which should be overriden by model specific calibrated >> data. > > Ah. Someone thought it was a good idea to provide the "one ring to rule > them all". Nice. Yes, that was a bad idea. wl1251-nvs.bin in linux-firmware.git should be renamed to wl1251-nvs.bin.example, or something like that, as it should be only installed to a real system only if there's no real calibration data available (only for developers to use, not real users). >> But overwriting that one file is not possible as it next update of >> linux-firmware package will overwrite it back. It break any normal usage >> of package management. >> >> Also it is ridiculously broken by design if some "boot" files needs to >> be overwritten to initialize hardware properly. To not break booting you >> need to overwrite that file before first boot. But without booting >> device you cannot read calibration data. So some hack with autoreboot >> after boot is needed. Providing the calibration data via Device Tree is the proper way to solve this. Yes yes, I know N900 doesn't support it but that's a deficiency in N900, not Linux. >> And how to detect that we have real overwritten calibration data and >> not default one from linux-firmware? Any heuristic or checks will be >> broken here. And no, nothing like you need to reboot your device now >> (and similar concept) from windows world is not accepted. > > Well. After reading and creating calibration data you could just rebind > the driver to the device to have it probed again. Or load wl1251 as a module and make sure calibration data is installed before the module is loaded. LEDE does that with ath10k: https://git.lede-project.org/?p=source.git;a=blob;f=target/linux/ar71xx/base-files/etc/hotplug.d/firmware/11-ath10k-caldata;h=97875bd79a579a0010da3f60324b6ec966fe9c6a;hb=HEAD > But yeah, the default one from linux-firmware should never have been > there in the first place. Agreed. -- Kalle Valo
