Re: [PATCH v2 2/2] asm-generic: Add new pci.h and use it

[Arnd Bergmann <arnd@arndb.de>]

On Tue, Jul 19, 2022 at 12:55 PM Stafford Horne <shorne@gmail.com> wrote:

> diff --git a/drivers/comedi/drivers/comedi_isadma.c b/drivers/comedi/drivers/comedi_isadma.c
> index 700982464c53..508421809128 100644
> --- a/drivers/comedi/drivers/comedi_isadma.c
> +++ b/drivers/comedi/drivers/comedi_isadma.c
> @@ -104,8 +104,10 @@ unsigned int comedi_isadma_poll(struct comedi_isadma *dma)
>
>         flags = claim_dma_lock();
>         clear_dma_ff(desc->chan);
> +#ifdef CONFIG_X86_32
>         if (!isa_dma_bridge_buggy)
>                 disable_dma(desc->chan);
> +#endif

There is a logic mistake here: if we are on something other than x86-32,
this always needs to call the disable_dma()/enable_dma().

Not sure how to best express this in a readable way, something like this
would work:

#ifdef CONFIG_X86_32
        if (!isa_dma_bridge_buggy)
#endif
               disable_dma(desc->chan);


or possibly at the start of this file, a

#ifndef CONFIG_X86_32
#define isa_dma_bridge_buggy 0
#endif

Or we could try to keep the generic definition in a global header
like linux/isa-dma.h.

> --- a/sound/core/isadma.c
> +++ b/sound/core/isadma.c
> @@ -73,8 +73,10 @@ unsigned int snd_dma_pointer(unsigned long dma, unsigned int size)
>
>         flags = claim_dma_lock();
>         clear_dma_ff(dma);
> +#ifdef CONFIG_X86_32
>         if (!isa_dma_bridge_buggy)
>                 disable_dma(dma);
> +#endif
>         result = get_dma_residue(dma);
>         /*

Same here.

         Arnd