Arend van Spriel <aspriel@xxxxxxxxx> writes: > On Tue, Oct 5, 2021 at 10:02 AM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >> >> Hi Kalle, >> >> On 10/5/21 7:36 AM, Kalle Valo wrote: >> > Hans de Goede <hdegoede@xxxxxxxxxx> writes: >> > >> >> In some cases the EFI-var stored nvram contains "ccode=ALL", "ccode=XV" >> >> or "ccode=XT", to specify "worldwide" compatible settings, but these >> >> ccode-s do not work properly. "ccode=ALL" causes channels 12 and 13 to >> >> not be available, "ccode=XV" / "ccode=XT" may cause all 5GHz channels >> >> to not be available. >> >> >> >> ccode="ALL" and ccode="XV" where already being replaced with ccode="X2" >> >> with a bit of special handling for nvram settings coming from an EFI >> >> variable. Extend this handling to also deal with nvram settings from >> >> EFI variables which contain "ccode=XT", which has similar issues to >> >> "ccode=XV". >> >> >> >> This fixes 5GHz wifi not working on the HP ElitePad 1000 G2. >> >> >> >> This was also tested on a Lenovo Thinkpad 8 tablet which also uses >> >> "ccode=XT" and this causes no adverse effects there. >> >> >> >> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> >> > >> > To me worldwide compatible settings mean that channels 12 and 13 should >> > be disabled, so I'm quite hesitant about this patch. >> >> The X2 setting puts channel 12 and 13 in passive / listen-only modes >> and only starts using them if there is an AP on them. >> >> AFAIK this is the same with the XT/XV settings. The problem is that the XT >> setting results in 5G not being available on some boards even though the >> hw supports it. >> >> Also note that we already use the X2 setting for any EFI supplied nvram >> files where ccode=ALL or ccode=XV, this just extends the handling we >> already have to also patch ccode=XT. > > I am not overly excited about this approach that is already in use. > AFAIK these worldwide codes are tailored for specific > devices/customers based on their RF components. Using it as fallback > for other devices in such a generic way could even result in exceeding > regulatory limits. However, I do not have a better solution for this. > I am surprised to learn there are nvram out there with ccode=ALL as > that is for internal use only, but if these devices has SROM than the > nvram value is ignored. Hopefully, that is the case although given the > fact that changing it to X2 helps suggests otherwise :-( What's the conclusion? Should I take this or drop it? -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
