Martin Blumenstingl <[email protected]> writes: > On Sat, Dec 22, 2018 at 7:09 AM Daniel F. Dickinson > <[email protected]> wrote: >> >> ath9k_of_init() function[0] was initially written on the assumption that >> if someone had an explicit ath9k OF node that "there must be something >> wrong, why would someone add an OF node if everything is fine"[1] >> (Quoting Martin Blumenstingl <[email protected]>) >> >> "it turns out it's not that simple. with your requirements I'm now aware >> of two use-cases where the current code in ath9k_of_init() doesn't work >> without modifications"[1] >> >> The "your requirements" Martin speaks of is the result of the fact that I >> have a device (PowerCloud Systems CR5000) has some kind of default - not >> unique mac address - set and requires to set the correct MAC address via >> mac-address devicetree property, however: >> >> "some cards come with a physical EEPROM chip [or OTP] so "qca,no-eeprom" >> should not be set (your use-case). in this case AH_USE_EEPROM should be >> set (which is the default when there is no OF node)"[1] >> >> The other use case is: >> >> the firmware on some PowerMac G5 seems to add a OF node for the ath9k >> card automatically. depending on the EEPROM on the card AH_NO_EEP_SWAP >> should be unset (which is the default when there is no OF node). see [3] >> >> After this patch to ath9k_of_init() the new behavior will be: >> >> if there's no OF node then everything is the same as before >> if there's an empty OF node then ath9k will use the hardware EEPROM >> (before ath9k would fail to initialize because no EEPROM data was >> provided by userspace) >> if there's an OF node with only a MAC address then ath9k will use >> the MAC address and the hardware EEPROM (see the case above) >> with "qca,no-eeprom" EEPROM data from userspace will be requested. >> the behavior here will not change >> [1] >> >> Martin provides additional background on EEPROM swapping[1]. >> >> Thanks to Christian Lamparter <[email protected]> for all his help on >> troubleshooting this issue and the basis for this patch. >> >> Fixes: 138b41253d9c ("ath9k: parse the device configuration from an OF node") >> >> [0]https://elixir.bootlin.com/linux/v4.20-rc7/source/drivers/net/wireless/ath/ath9k/init.c#L615 >> [1]https://github.com/openwrt/openwrt/pull/1645#issuecomment-448027058 >> [2]https://github.com/openwrt/openwrt/pull/1613 >> [3]https://patchwork.kernel.org/patch/10241731/ > > +Cc Bas Vermeulen: can you please try Daniel's patch on your PowerMac > G5? I hope that this replaces your "endian_check" module parameter! > >> Signed-off-by: Daniel F. Dickinson <[email protected]> > > Reviewed-by: Martin Blumenstingl <[email protected]> > (to me the description makes sense, but that said: I contributed some > of the description) > > as well as: > Tested-by: Martin Blumenstingl <[email protected]> > (on my BT HomeHub 5A - which sets qca,no-eeprom - using OpenWrt, which > is currently running backports v4.19.7)
Daniel noticed that patchwork dropped Martin's reply, adding it to patchwork now. -- Kalle Valo
