Re: [PATCH] wifi: mt7601u: update firmware path

From: Kalle Valo
Date: Wed May 24 2023 - 03:47:37 EST

Kalle Valo <kvalo@xxxxxxxxxx> writes:

> Daniel Golle <daniel@xxxxxxxxxxxxxx> writes:
>> mt7601u.bin was moved to mediatek/ folder in linux-wireless via commit
>> 8451c2b1 ("mt76xx: Move the old Mediatek WiFi firmware to mediatek")
>> and linux-firmware release 20230515.
> Why was it moved?

Here's the link to the commit in linux-firmware:

It would be good to include that in the commit log. Unfortunately the
linux-firmware commit doesn't explain why the change is made, oh well.

>> --- a/drivers/net/wireless/mediatek/mt7601u/usb.h
>> +++ b/drivers/net/wireless/mediatek/mt7601u/usb.h
>> @@ -8,7 +8,7 @@
>> #include "mt7601u.h"
>> -#define MT7601U_FIRMWARE "mt7601u.bin"
>> +#define MT7601U_FIRMWARE "mediatek/mt7601u.bin"
> How do we handle backwards compatibility? We have a rule that old
> userspace needs to work with new kernel and this change breaks that.

Luckily the linux-firmware commit added symlinks so that won't break the
backward compatibility. But I think in the driver we still need to
support both the old and new location for several years. So the driver
should first try the new location, next the old location and only after
that fail.