# DMA Cache problem on PPC8248.

- List: linuxppc-dev
- 2 messages, 2 authors
- Page: https://ratatoskr.run/linuxppc-dev/2008/08/9444550/t

## DMA Cache problem on PPC8248.

- From: Jayasri Sangu \<hidden\>
- Date: 2008-08-19 21:58:55 
- Message: https://ratatoskr.run/linuxppc-dev/2008/08/9444550.md

```text
Hi All,

   We are using PPC8248 provided by freescale and the kernel  2.6.10. I believe we have cache problem.

  We are allocating DMA buffers in our driver. If we increase the DMA buffer size the board hangs/halts(when try to load more applications).

  If we reduce the DMA buffer size, then we can run all our applications.

   Is there any way I can get around this problem.


Thanks
Jayasri




```

## Re: \[gmail\] DMA Cache problem on PPC8248.

- From: Marc Leeman \<hidden\>
- Date: 2008-08-20 07:02:36 
- Message: https://ratatoskr.run/linuxppc-dev/2008/08/9444557.md

```text
>    We are using PPC8248 provided by freescale and the kernel  2.6.10. I believe we have cache problem.
>   We are allocating DMA buffers in our driver. If we increase the DMA buffer size the board hangs/halts(when try to load more applications).
>   If we reduce the DMA buffer size, then we can run all our applications.
>    Is there any way I can get around this problem.

Have a look at the u-boot code for the 8245; I once submitted a patch
for such a problem on an XPC8245 (experimental MPC8245). It's still in
the code; but disabled right now.

It might be the same silicon bug.

-- 
  greetz, marc
Yeah, yeah, yeah nothing like a bomb to sober me up, I'm fine.
	Crichton - Suns and Lovers
crichton 2.6.26 #1 PREEMPT Tue Jul 29 21:17:59 CDT 2008 armv5tel GNU/Linux
```