Re: [PATCH] firmware_class: Add firmware filename overrides

From: Marcel Holtmann
Date: Thu Mar 05 2015 - 12:39:42 EST


Hi Charles,

> Specifically this was motivated by a situation where we have one
> device with a dual-sourced touchscreen. Both use the same driver but
> have different hardware & fw. Our FW updating software therefore,
> needs to be able to update with the correct FW and detect all this at
> runtime due to a read-only partition (so moving the firmware binaries
> around isn't really an option)
> Here the device has only one touchscreen at a time, but it isn't known
> until run-time which will be present.
>
> So in this case the driver is serving the same function in each
> situation (running a touchscreen) but may be working with different
> hardware.
>
> Another situation where I've personally wanted this functionality is
> on a device that uses the same touch driver for both a touchscreen and
> a touchpad on the same device. If the driver only grabs a copy of FW
> from, say, /lib/firmware/touch_fw.bin then you either need to move the
> firmware binaries around on disk to update either device, or have a
> change like this that allows you to override which filename it loads.
> The moving option is not viable if you're using a RO filesystem.

what is the actual problem here? We have drivers that load multiple firmware files and we have drivers that pick a different firmware depending on some parameters it reads from the device.

Seems this is all possible already at the moment with the existing framework. You just need to update the drivers to operate properly.

Regards

Marcel

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