On Thu, Mar 2, 2023, at 05:12, Baoquan He wrote: > On 03/01/23 at 03:06pm, Arnd Bergmann wrote: > > Yeah, defining mmiowb() to wmb() directly is also good to me. I tried > to comb including sequence and find where asm/io.h is included, but > failed. Mainly asm/mmiowb.h including asm/io.h will cause below > compiling error, the asm/io.h need see mmiowb_set_pending which is > defnined in asm-generic/mmiowb.h. Moving asm-generic/mmiowb.h to above > asm/io.h can also fix the compiling error. > > ============= > diff --git a/arch/mips/include/asm/mmiowb.h b/arch/mips/include/asm/mmiowb.h > index a40824e3ef8e..cae2745935bc 100644 > --- a/arch/mips/include/asm/mmiowb.h > +++ b/arch/mips/include/asm/mmiowb.h > @@ -2,10 +2,8 @@ > #ifndef _ASM_MMIOWB_H > #define _ASM_MMIOWB_H > > +#include <asm-generic/mmiowb.h> > #include <asm/io.h> > > #define mmiowb() iobarrier_w() > - > -#include <asm-generic/mmiowb.h> > - > #endif /* _ASM_MMIOWB_H */ According to the comment in asm-generic/mmiowb.h, the intention is to have the mmiowb definition before the #include, though this would only be necessary if there was an "#ifndef mmiowb" fallback in that file. If the definition to wmb() works, I'd go for that one and leave the include order unchanged. Arnd