On 15-12-2016 16:33, Pali Rohár wrote: > On Thu Dec 15 09:18:44 2016 Kalle Valo <kvalo@xxxxxxxxxxxxxx> wrote: >> (Adding Luis because he has been working on request_firmware() lately) >> >> Pali Rohár <pali.rohar@xxxxxxxxx> writes: >> >>>>> So no, there is no argument against... request_firmware() in >>>>> fallback mode with userspace helper is by design blocking and >>>>> waiting for userspace. But waiting for some change in DTS in >>>>> kernel is just nonsense. >>>> >>>> I would just mark the wlan device with status = "disabled" and >>>> enable it in the overlay together with adding the NVS & MAC info. >>> >>> So if you think that this solution make sense, we can wait what net >>> wireless maintainers say about it... >>> >>> For me it looks like that solution can be: >>> >>> extending request_firmware() to use only userspace helper >> >> I haven't followed the discussion very closely but this is my preference >> what drivers should do: >> >> 1) First the driver should do try to get the calibration data and mac >> address from the device tree. >> > > Ok, but there is no (dynamic, device specific) data in DTS for N900. So 1) is noop. Uhm. What do you mean? You can propose a patch to the DT bindings [1] to get it in there and create your N900 DTB or am I missing something here. Are there hardware restrictions that do not allow you to boot with your own DTB. >> 2) If they are not in DT the driver should retrieve the calibration data >> with request_firmware(). BUT with an option for user space to >> implement that with a helper script so that the data can be created >> dynamically, which I believe openwrt does with ath10k calibration >> data right now. > > Currently there is flag for request_firmware() that it should fallback to user helper if direct VFS access not find needed firmware. > > But this flag is not suitable as /lib/firmware already provides default (not device specific) calibration data. > > So I would suggest to add another flag/function which will primary use user helper. I recall Luis saying that user-mode helper (fallback) should be discouraged, because there is no assurance that there is a user-mode helper so you might just be pissing in the wind. The idea was to have a dedicated API call that explicitly does the request towards user-space. By the way, are we talking here about wl1251 device or driver as you also mentioned wl12xx? I did not read the entire thread. Regards, Arend
