Messages in this thread | ![/](/images/icornerl.gif) | | From | Geert Uytterhoeven <> | Date | Mon, 8 Apr 2024 10:23:25 +0200 | Subject | Re: [PATCH 0/1] m68k: Handle HAS_IOPORT dependencies |
| |
Hi Arnd,
On Fri, Apr 5, 2024 at 1:26 PM Arnd Bergmann <arnd@kernel.org> wrote: > On Fri, Apr 5, 2024, at 12:16, Geert Uytterhoeven wrote: > > On Wed, Apr 3, 2024 at 8:35 PM Arnd Bergmann <arnd@kernel.org> wrote: > > Michael is worried about non-ISA drivers using inb() and friends. > > At some point in time (i.e. eons ago), we were told it was better to > > use in[bwl]()/read[bwl]() instead of directly dereferencing volatile > > pointers... > > It's definitely still better to use an abstraction layer for MMIO > accesses using inline asm instructions than open-coding the > volatile pointer dereferences. Over time we have gotten better > at defining which of the available abstractions should be used > for a given bus, so inb()/outb() is now only really used for > things derived from ISA in some form, including e.g. PCI and LPC.
Indeed. Nowadays the consensus is that readl() and friends should always perform little-endian accesses, thus implying byte-swapping on big-endian platforms, but most of the m68k drivers were written long before that enlightenment...
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68korg
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
| ![\](/images/icornerr.gif) |