Re: sound/driver/hda and ia64

On Mon, 2 Oct 2006 14:59:59 -0400
John Baldwin <jhb_at_freebsd.org> wrote:
> On Monday 02 October 2006 08:50, Ariff Abdullah wrote:
> > On Mon, 02 Oct 2006 12:22:33 +0000
> > Poul-Henning Kamp <phk_at_phk.freebsd.dk> wrote:
> > > 
> > > During a "make universe" ia64 fails with the following errors.
> > > 
> > > I wouldn't expect a sound driver to call any of those functions
> > > at all, what's going on ?
> > > 
> > > 
[....]
> > >
> > 
> > I wish BUS_DMA_NOCACHE has real meaning (like what NetBSD did)
> > since uncached DMA is pretty much guarantee to make the driver
> > works on broken i386/amd86 hardwares.
> > 
> > Should we just narrow this down to i386/amd64 , or give
> > BUS_DMA_NOCACHE a real meaning as part of bus_dmamem_alloc() ?
> > 
> > I'm open for suggestion.
> 
> I can probably fix NOCACHE for i386/amd64 for the bus_dmamem_alloc()
> case. Try this patch:
> 
> --- //depot/vendor/freebsd/src/sys/amd64/amd64/busdma_machdep.c	2006/06/01 
> 04:50:42
> +++ //depot/user/jhb/acpipci/amd64/amd64/busdma_machdep.c	2006/10/02 18:58:21
> _at__at_ -48,6 +48,7 _at__at_
>  #include <machine/atomic.h>
>  #include <machine/bus.h>
>  #include <machine/md_var.h>
> +#include <machine/specialreg.h>
>  
>  #define MAX_BPAGES 8192
>  
> _at__at_ -522,6 +523,9 _at__at_
>  	} else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) {
>  		printf("bus_dmamem_alloc failed to align memory properly.");
>  	}
> +	if (flags & BUS_DMA_NOCACHE)
> +		pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize,
> +		    PAT_UNCACHEABLE);
>  	CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
>  	    __func__, dmat, dmat->flags, ENOMEM);
>  	return (0);
> --- //depot/vendor/freebsd/src/sys/i386/i386/busdma_machdep.c	2006/09/26 
> 23:16:33
> +++ //depot/user/jhb/acpipci/i386/i386/busdma_machdep.c	2006/10/02 18:58:21
> _at__at_ -51,6 +51,7 _at__at_
>  #include <machine/atomic.h>
>  #include <machine/bus.h>
>  #include <machine/md_var.h>
> +#include <machine/specialreg.h>
>  
>  #define MAX_BPAGES 512
>  #define BUS_DMA_COULD_BOUNCE	BUS_DMA_BUS3
> _at__at_ -530,6 +531,9 _at__at_
>  	} else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) {
>  		printf("bus_dmamem_alloc failed to align memory
>  		properly.\n");
>  	}
> +	if (flags & BUS_DMA_NOCACHE)
> +		pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize,
> +		    PAT_UNCACHEABLE);
>  	CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
>  	    __func__, dmat, dmat->flags, ENOMEM);
>  	return (0);
> 
> 
I guess these are what we're looking for. I can't tell whether it
really works or not (finding such buggy hardware is quite difficult),
but this will make lot of things easier for drivers.

Any objections? I guess you should go ahead, John.


--
Ariff Abdullah
FreeBSD

... Recording in stereo is obviously too advanced
    and confusing for us idiot ***** users :P ........