"Daniel F. Dickinson" <cshored@xxxxxxxxxxxxx> 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 <martin.blumenstingl@xxxxxxxxxxxxxx>) > > "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 <chunkeey@xxxxxxxxx> for all his help on > troubleshooting this issue and the basis for this patch. > > [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/ > > Fixes: 138b41253d9c ("ath9k: parse the device configuration from an OF node") > Reviewed-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> > Tested-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> > Signed-off-by: Daniel F. Dickinson <cshored@xxxxxxxxxxxxx> > Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx> Patch applied to ath-next branch of ath.git, thanks. ce938231bd3b ath9k: Avoid OF no-EEPROM quirks without qca,no-eeprom -- https://patchwork.kernel.org/patch/10741449/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
