Ok, I think I had too much patching going on (I switched from 4.8.4 kernel drivers to media_build) so I started from scratch with a fresh update to kernel 4.8.7. First I applied the dma stuff in this order: (from https://patchwork.linuxtv.org/patch/37395/raw/) v2-18-31-gp8psk-don-t-do-DMA-on-stack.patch (from https://patchwork.linuxtv.org/patch/37386/raw/) v2-19-31-gp8psk-don-t-go-past-the-buffer-size.patch (from https://patchwork.linuxtv.org/patch/37929/raw/) media-gp8psk-fix-gp8psk_usb_in_op-logic.patch It works fine at this point but we still have the attach bug. Then I applied: (from https://patchwork.linuxtv.org/patch/38040/raw/) Question-about-2-gp8psk-patches-I-noticed-and-possible-bug..patch Attach bug is fixed, tuning works, module unloads without crashing. Everything seems ok! I think the gp8psk issues are resolved with the above 4 patches. As you know, there are some other drivers which attach the same way as gp8psk was. Thanks for your help & patience! One quick question.. Shouldn't gp8psk_fe be listed in the "used by" column of dvb_usb_gp8psk or the other dvb_* modules?: Module Size Used by gp8psk_fe 3803 1 dvb_usb_gp8psk 7344 19 dvb_usb 17495 1 dvb_usb_gp8psk dvb_core 62327 1 dvb_usb -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html