fix oops in dma_unmap_page on not coherent mips platforms

fix oops in dma_unmap_page on not coherent mips platforms

[Jan Nikitenko]

dma_cache_wback_inv() expects virtual address, but physical was provided
due to translation via plat_dma_addr_to_phys().
If replaced with dma_addr_to_virt(), page fault oops from dma_unmap_page()
is gone on au1550 platform.

Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com>
---
 arch/mips/mm/dma-default.c |    2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index 5b98d0e..5f336c1 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -222,7 +222,7 @@ void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
 	if (!plat_device_is_coherent(dev) && direction != DMA_TO_DEVICE) {
 		unsigned long addr;
 
-		addr = plat_dma_addr_to_phys(dma_address);
+		addr = dma_addr_to_virt(dma_address);
 		dma_cache_wback_inv(addr, size);
 	}
 

Re: fix oops in dma_unmap_page on not coherent mips platforms

[Atsushi Nemoto]

On Fri, 28 Nov 2008 08:52:58 +0100, Jan Nikitenko <jan.nikitenko@gmail.com> wrote:
> dma_cache_wback_inv() expects virtual address, but physical was provided
> due to translation via plat_dma_addr_to_phys().
> If replaced with dma_addr_to_virt(), page fault oops from dma_unmap_page()
> is gone on au1550 platform.
> 
> Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com>
> ---
>  arch/mips/mm/dma-default.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
> index 5b98d0e..5f336c1 100644
> --- a/arch/mips/mm/dma-default.c
> +++ b/arch/mips/mm/dma-default.c
> @@ -222,7 +222,7 @@ void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
>  	if (!plat_device_is_coherent(dev) && direction != DMA_TO_DEVICE) {
>  		unsigned long addr;
>  
> -		addr = plat_dma_addr_to_phys(dma_address);
> +		addr = dma_addr_to_virt(dma_address);
>  		dma_cache_wback_inv(addr, size);
>  	}

Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>

I'm also wondering why dma_map_page and dma_unmap_page are using
dma_cache_wback_inv instead of __dma_sync.  They also lack special
r10000 handling.  Hmm...

---
Atsushi Nemoto

Re: fix oops in dma_unmap_page on not coherent mips platforms

[Ralf Baechle]

> dma_cache_wback_inv() expects virtual address, but physical was provided
> due to translation via plat_dma_addr_to_phys().
> If replaced with dma_addr_to_virt(), page fault oops from dma_unmap_page()
> is gone on au1550 platform.
> 
> Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com>

Applied, finally ...

  Ralf

Re: fix oops in dma_unmap_page on not coherent mips platforms

[Atsushi Nemoto]

On Sat, 14 Mar 2009 00:00:49 +0100, Ralf Baechle <ralf@linux-mips.org> wrote:
> > dma_cache_wback_inv() expects virtual address, but physical was provided
> > due to translation via plat_dma_addr_to_phys().
> > If replaced with dma_addr_to_virt(), page fault oops from dma_unmap_page()
> > is gone on au1550 platform.
> > 
> > Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com>
> 
> Applied, finally ...

Good news!

And please take a look at this too:
http://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=1232638931-6203-1-git-send-email-anemo%40mba.ocn.ne.jp

---
Atsushi Nemoto