Re: [EXT] Re: [PATCH v7 4/5] firmware: imx: add driver for NXP EdgeLock Enclave

[Sascha Hauer <s.hauer@pengutronix.de>]

On Tue, Oct 01, 2024 at 07:49:39AM +0000, Pankaj Gupta wrote:
> >> >Either compile the firmware into the kernel or the ELE driver as module.
> >>
> >> Cannot compile as part of Firmware.
> >> There are OTA scenarios where the latest FW, that is downloaded to 
> >> replace the image in RFS, and FW needs to be re-init with this new 
> >> image, by putting the Linux to power-down state.
> >
> >> ELE driver is compiled as module only, by default. But if someone like 
> >> to make it as in-line to kernel image, still it should work.
> 
> > I am also not very happy with the situation that we can't compile drivers
> into the kernel and just get the firmware later once it is available.
> 
> Driver is enabling the ROM API supports at probe time. 
> And, once the rootfs is available, and the Firmware image is loaded, then it
> will enable the complete set of FW API(s), along with ROM API(s).
> 
> Hence, Driver can be compiled into the kernel to enable ELE-ROM API(s).

I see what the code does, I just don't think that it's safe to assume
that the rootfs will be mounted after the 50*20ms timeout you use.

I also think that it's a valid usecase for builtin code to retry
firmware loading after the rootfs has been mounted. This should be
integrated into the firmware loading code though and not be done as a
driver specific hack.

Anyway, it won't be me who merges this code and I am just telling you
that you'll likely have a problem getting this upstream as is.

Sascha

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