On Wed, Mar 01, 2023 at 04:38:10AM +0000, Edward Cree wrote: > On 01/03/2023 03:42, Baoquan He wrote: > > diff --git a/drivers/net/ethernet/sfc/io.h b/drivers/net/ethernet/sfc/io.h > > index 30439cc83a89..07f99ad14bf3 100644 > > --- a/drivers/net/ethernet/sfc/io.h > > +++ b/drivers/net/ethernet/sfc/io.h > > @@ -70,7 +70,7 @@ > > */ > > #ifdef CONFIG_X86_64 > > /* PIO is a win only if write-combining is possible */ > > -#ifdef ARCH_HAS_IOREMAP_WC > > +#ifdef ioremap_wc > > #define EFX_USE_PIO 1 > > #endif > > #endif > > So I don't know how valid what we're doing here is... Well, x86 defines ARCH_HAS_IOREMAP_WC unconditionally, so it doesn't affect you ... but you raise a good question about how a driver can determine if it's actually getting WC memory.
