Don't define an empty struct bsg_class_device if !CONFIG_BLK_DEV_BSG. It's embedded in struct request_queue, but there we have #if defined(CONFIG_BLK_DEV_BSG) struct bsg_class_device bsg_dev; #endif anyway. Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@xxxxxxxxxxx> --- At first I considered dropping the #ifdef around request_queue.bsg_dev, but that would make the code more error-prone. include/linux/bsg.h | 1 - 1 files changed, 1 deletion(-) --- a/include/linux/bsg.h +++ b/include/linux/bsg.h @@ -60,7 +60,6 @@ struct bsg_class_device { extern int bsg_register_queue(struct request_queue *, const char *); extern void bsg_unregister_queue(struct request_queue *); #else -struct bsg_class_device { }; #define bsg_register_queue(disk, name) (0) #define bsg_unregister_queue(disk) do { } while (0) #endif With kind regards, Geert Uytterhoeven Software Architect Sony Network and Software Technology Center Europe The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium Phone: +32 (0)2 700 8453 Fax: +32 (0)2 700 8622 E-mail: Geert.Uytterhoeven@xxxxxxxxxxx Internet: http://www.sony-europe.com/ Sony Network and Software Technology Center Europe A division of Sony Service Centre (Europe) N.V. Registered office: Technologielaan 7 · B-1840 Londerzeel · Belgium VAT BE 0413.825.160 · RPR Brussels Fortis Bank Zaventem · Swift GEBABEBB08A · IBAN BE39001382358619