Hi, I could not understand why so many large WiFi chip vendors retreat to stop maintaining WiFi SDIO chips to mainline Linux kernel, and to settle it's chip support to out of the tree, use its own SDK and proprietary kernel tree to source.codeaurora.org or private repository which are not compatible to mainline stable kernel, the kernel configures are also different. I looked at the following link, the mwifiex and mwifiex_sdio support the Marvell (NXP) 88W88 chipset, but only kernel 4.19 was able to build and to run, kernel 5 cannot support 88W88 chipset, any more. Same to Qualcomm, the old Atheros WiFi modules are supported, the QCA-9377-3 chipset is in source.codeaurora.org only supported by old kernel 4.9. Given the OE/Yocto poky kernel build is based on a mainline stable kernel repository, how can I build kernel 5 for 88W88 chipset or QCA-9377-3 from source.codeaurora.org or private repository? Or which WiFi vendors are still well maintaining the WiFi chips for kernel 5, the only sensible solution is to switch WiFi SDIO chips? Appreciate your advice and comments. https://wireless.wiki.kernel.org/en/users/drivers Thank you very much. Kind regards, jupiter