On Thursday 24 November 2016 19:11:39 Sebastian Reichel wrote: > Hi, > > On Thu, Nov 24, 2016 at 05:49:33PM +0100, Pali Rohár wrote: > > On Thursday 24 November 2016 17:08:30 Sebastian Reichel wrote: > > > On Thu, Nov 24, 2016 at 04:20:45PM +0100, Pali Rohár wrote: > > > > On Thursday 24 November 2016 16:13:17 Sebastian Reichel wrote: > > > > > On Thu, Nov 24, 2016 at 09:33:29AM +0100, Pali Rohár wrote: > > > > > > On Thursday 24 November 2016 08:51:04 Pavel Machek wrote: > > > > > > > > > "ifconfig hw ether XX" normally sets the address. I > > > > > > > > > guess that's ioctl? > > > > > > > > > > > > > > > > This sets temporary address and it is ioctl. IIRC same > > > > > > > > as what ethtool uses. (ifconfig is already > > > > > > > > deprecated). > > > > > > > > > > > > > > > > > And I guess we should use similar mechanism for > > > > > > > > > permanent address. > > > > > > > > > > > > > > > > I'm not sure here... Above ioctl ↑↑↑ is for changing > > > > > > > > temporary mac address. But here we do not want to > > > > > > > > change permanent mac address. We want to tell kernel > > > > > > > > driver current permanent mac address which is stored > > > > > > > > > > > > > > Well... I'd still use similar mechanism :-). > > > > > > > > > > > > Thats problematic, because in time when wlan0 interface is > > > > > > registered into system and visible in ifconfig output it > > > > > > already needs to have permanent mac address assigned. > > > > > > > > > > > > We should assign permanent mac address before wlan0 of > > > > > > wl1251 is registered into system. > > > > > > > > > > You can just add the MAC address to the NVS data, which is > > > > > also required for the device initialization. > > > > > > > > NVS data file has fixed size, there is IIRC no place for it. > > > > > > > > But one of my suggestion was to use another request_firmware > > > > for MAC address. So this is similar to what you are proposing, > > > > as NVS data are loaded by request_firmware too... > > > > > > Just append it to NVS data and modify the size check accordingly? > > > > First that would mean to have request_firmware() function which > > will not use direct VFS access, but instead use userspace helper. > > Permanent MAC is device specific init data, NVS is device specific > init data => load together. > > The userspace helper stuff is only needed to get the data from > the NAND calibration area on the fly. But it is needed... and currently request_firmware() prefer direct VFS access... > > NVS data file with some default values (not suitable for usage) is > > already present in linux-firmware and available in > > /lib/firmware/... > > You mentioned NVS data is fixed size, so this should be enough? > > switch(loaded_size) > case IMAGE_SIZE + MAC_SIZE: > /* extract mac */ > /* fallthrough */ > case IMAGE_SIZE: > /* load NVS */ > break; > default: > /* fail */ > } > > > Also I'm not sure if such thing is allowed by license: > > https://git.kernel.org/cgit/linux/kernel/git/firmware/linux-firmwar > > e.git/tree/LICENCE.ti-connectivity > > concating data is not a modification, otherwise you can't > put the file in a filesystem. Ok, if net maintainers agree. > > > > > I wonder if those information could be put into DT. Iirc some > > > > > network devices get their MAC address from DT. Maybe we can > > > > > add all NVS info to DT? How much data is it? > > > > > > > > Proprietary, signed and closed bootloader NOLO does not support > > > > DT. So for booting you need to append DTS file to kernel > > > > image. > > > > > > Yeah, so NOLO without U-Boot will depend on userspace to fixup > > > DT. > > > > > > > U-Boot is optional and can be used as intermediate bootloader > > > > between NOLO and kernel. But still it has problems with reading > > > > from nand, so cannot read NVS data nor MAC address. > > > > > > It may in the future? > > > > I already tried that, but I failed. I was not able to access N900's > > nand from u-boot. No idea where was problem... > > > > And if somebody fix onenand in u-boot, then needs to reimplement > > Nokia's proprietary parser of that partition where is stored NVS > > and mac address && make this support in upstream u-boot. > > Are we talking about this? > > https://github.com/community-ssu/libcal/blob/master/cal.c > > That's ~1k loc for read-only. Yes. There is also read-only alternative library: https://github.com/pali/0xFFFF/blob/master/src/cal.c But still, this is proprietary format useful only for one device (or two) and I do not know if such thing could be accepted by u-boot developers... > Getting NAND working looks harder than porting this to me. Right. > > So... I doubt it will be in any future. > > > > + no men power > > yeah :( > > But with that reasoning you should just extract the NVS data > from NAND and put it in your rootfs. Not a clean solution. Some rootfs parts can used as readonly. And normally rootfs is flashed into nand, so I still will say that roofs (image) should not contain any device specific data. > > > > > Userspace application can add all those information to the DT > > > > > using a DT overlay. Also the u-boot could parse and add it at > > > > > some point in the future. > > > > > > > > In case when wl1251 is statically linked into kernel image, it > > > > is loaded and initialized before even userspace applications > > > > starts. > > > > > > > > So no... adding NVS data or MAC address into DT or DT overlay > > > > is not a solution. > > > > > > Actually with data loaded from DT you *can* load data quite early > > > in the boot process, while your suggestions always require > > > userspace. So you argument against yourself? > > > > You cannot add DTS in uboot (no support). > > AFAIK that's supported: > > http://www.denx.de/wiki/DULG/LinuxFDTBlob > > "Note that U-Boot makes some automatic modifications to the blob > before passing it to the kernel - mainly adding and modifying > information that is learnt at run-time." I mean we do not have support for due to n900 nand. > > And if you modify DTS on running kernel from userspace, then it is > > too late when wl1251 is statically linked into kernel image. > > > > wl1251 will not wait until some userspace modify DTS and add > > data... > > if (nvs info missing) > return -EPROBE_DEFER; Forever? Only N times? How long? Only N second? Here we do not know if userspace is going to send data or not. My guess is that such code will not be accepted into net/wireless subsystem or drivers by maintainers. > > But request_firmware() in fallback mode *can* wait for userspace so > > wl1251 can postpone its operation until mdev/udev/whatever starts > > listening for events and push needed firmware data to kernel. > > As you said one workaround is waiting. That's not a solution, that > only works with request_firmware(). Yes, but request_firmware() uses interaction with userspace. Your proposed solution does not do any interaction with userspace that some process needs to fill missing data into DT. And request_firmware() is already used for loading NVS data. > > 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 and load mac address also via request_firmware() either by appending it into NVS data or via separate call -- Pali Rohár pali.rohar@xxxxxxxxx
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