It looks 2.6.19 or 2.6.20 does not work on DECStations. When I post a patch (commit f431baa55abf8adeed0c718b51deacbc151f58f1), I just tried to not change behavior of existing codes, but it seems dec/int-handler.S had been broken since its previous commit 937a801576f954bd030d7c4a5a94571710d87c0b. The caller of plat_irq_dispatch do setup/restore TI_REGS($28), so dec's plat_irq_dispatch should not do it, and there is no need to adjust RA. Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx> --- diff --git a/arch/mips/dec/int-handler.S b/arch/mips/dec/int-handler.S index b251ef8..00cecdc 100644 --- a/arch/mips/dec/int-handler.S +++ b/arch/mips/dec/int-handler.S @@ -264,9 +264,6 @@ srlv t3,t1,t2 handle_it: - LONG_L s0, TI_REGS($28) - LONG_S sp, TI_REGS($28) - PTR_LA ra, ret_from_irq j dec_irq_dispatch nop @@ -277,7 +274,6 @@ fpu: #endif spurious: - PTR_LA ra, _ret_from_irq j spurious_interrupt nop END(plat_irq_dispatch)