Hi, I'm using the 8250 driver on a ML300 based PPC board which uses interrupt vector 0 for the UART. is_real_interrupt() unfortunately interpretes IRQ0 as meaning no interrupt, so performance is kinda crap. How to fix? 8250.c is setup so that asm/serial.h is included after the definition of is_real_interrupt and the idea is that you can redefine it in your platform header if needed. Now, this doesn't work on PPC as the platform headers are included in asm/io.h AND asm/serial.h so they won't be reparsed the second time. I see 3 options: 1) Put an #ifndef is_real_interrupt around the is_real_interrupt definition so the platform header can define it's own independent of inclusion order. 2) A lot of platforms (but not all) define NO_IRQ to something sensible (-1). Define is_real_interrupt in terms of NO_IRQ instead of testing against 0. For the remaining platforms we could locally define NO_IRQ to 0 to keep the old behavior. 3) Put the redefine directly in asm/serial.h surrounded by an #ifdef CONFIG_XILINX_ML300 (ugly) Which solution is preferable? -- Bye, Peter Korsgaard - To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html