Hi,
On 4/15/23 17:25, Toke Høiland-Jørgensen wrote:
Álvaro Fernández Rojas <noltari@xxxxxxxxx> writes:
BCM63xx (Big Endian MIPS) devices store the calibration data in MTD
partitions but it needs to be swapped in order to work, otherwise it fails:
ath9k 0000:00:01.0: enabling device (0000 -> 0002)
ath: phy0: Ignoring endianness difference in EEPROM magic bytes.
ath: phy0: Bad EEPROM VER 0x0001 or REV 0x00e0
ath: phy0: Unable to initialize hardware; initialization status: -22
ath9k 0000:00:01.0: Failed to initialize device
ath9k: probe of 0000:00:01.0 failed with error -22
How does this affect other platforms? Why was the NO_EEP_SWAP flag set
in the first place? Christian, care to comment on this?
I knew this would come up. I've written what I know and remember in the
pull-request/buglink.
Maybe this can be added to the commit?
Link: https://github.com/openwrt/openwrt/pull/12365
| From what I remember, the ah->ah_flags |= AH_NO_EEP_SWAP; was copied verbatim from ath9k_of_init's request_eeprom.
Since the existing request_firmware eeprom fetcher code set the flag,
the nvmem code had to do it too.
In theory, I don't think that not setting the AH_NO_EEP_SWAP flag will cause havoc.
I don't know if there are devices out there, which have a swapped magic (which is
used to detect the endianess), but the caldata is in the correct endiannes (or
vice versa - Magic is correct, but data needs swapping).
I can run tests with it on a Netzgear WNDR3700v2 (AR7161+2xAR9220)
and FritzBox 7360v2 (Lantiq XWAY+AR9220). (But these worked fine.
So I don't expect there to be a new issue there).
The older platform_data code has a "endian_check" flag in
the ath9k_platform_data struct:
<https://github.com/torvalds/linux/blob/master/include/linux/ath9k_platform.h#L38>
Which enables the check and the endian-swapping (though it's disabled by default).
Cheers,
Christian
