On an Anbernic RG353V using the latest mainline kernel, the wifi (RTL8821CS) is in an unusable state on boot (no wireless adapter available) and I get the following kernel messages: [ 5.878711] rtw_8821cs mmc3:0001:1: Firmware version 24.11.0, H2C version 12 [ 6.218709] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x11080): -110 [ 6.218844] rtw_8821cs mmc3:0001:1: sdio write32 failed (0x11080): -110 [ 6.219136] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x10080): -110 [ 6.219230] rtw_8821cs mmc3:0001:1: sdio write32 failed (0x10080): -110 [ 6.219409] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x10040): -110 [ 6.219503] rtw_8821cs mmc3:0001:1: sdio write32 failed (0x10040): -110 [ 6.219706] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x11700): -110 [ 6.219800] rtw_8821cs mmc3:0001:1: sdio write32 failed (0x11700): -110 [ 6.219967] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x11708): -110 [ 6.220474] rtw_8821cs mmc3:0001:1: sdio write32 failed (0x11330): -110 [ 6.220673] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x1022c): -110 [ 6.220863] rtw_8821cs mmc3:0001:1: sdio write32 failed (0x1022c): -110 [ 6.220993] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x20): -110 [ 6.221570] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x11208): -110 [ 6.221695] rtw_8821cs mmc3:0001:1: sdio write32 failed (0x11208): -110 [ 6.222076] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x20): -110 [ 6.222195] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x24): -110 [ 6.222322] rtw_8821cs mmc3:0001:1: sdio read32 failed (0x28): -110 [ 6.222471] rtw_8821cs mmc3:0001:1: Failed to write 4608 byte(s) to SDIO port 0x0000840c [ 6.222510] rtw_8821cs mmc3:0001:1: failed to write data to rsvd page [ 6.222680] rtw_8821cs mmc3:0001:1: failed to download rsvd page [ 6.222851] rtw_8821cs mmc3:0001:1: failed to download firmware [ 6.223011] rtw_8821cs mmc3:0001:1: failed to setup chip efuse info [ 6.223033] rtw_8821cs mmc3:0001:1: failed to setup chip information [ 6.224013] rtw_8821cs: probe of mmc3:0001:1 failed with error -110 If I rmmod rtw_8821cs and modprobe rtw_8821cs, it actually becomes usable, at least for a while. After some time, many repeated messages like this appear: [ 1562.774009] rtw_8821cs mmc3:0001:1: timed out to flush queue 2 [ 1563.234018] rtw_8821cs mmc3:0001:1: timed out to flush queue 1 And I have to do the rmmod/modprobe trick again for it to start working again. I can always reproduce this on boot. I am using the latest mainline kernel, uboot and linux-firmware (I've also tried 6.5 kernel with the same result). kernel .config: https://github.com/human9/rg353v_linux/blob/main/linux_new.config dmesg: https://github.com/human9/rg353v_linux/blob/main/dmesg.txt