Messages in this thread | | | Date | Wed, 19 Nov 2008 19:41:27 +0100 | From | Pierre Ossman <> | Subject | Re: [patch 6/7] SDHCI: Check DMA for overruns at end of transfer |
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On Sun, 16 Nov 2008 00:05:08 +0000 Ben Dooks <ben-linux@fluff.org> wrote:
> On Fri, Nov 14, 2008 at 11:00:26PM +0100, Pierre Ossman wrote: > > > > I'm sorry, but I don't see how this is anywhere near acceptable. This > > should be a panic at the very least, and until this can be sorted out > > and avoided the driver should avoid using DMA on these chips. > > A panic won't help get the debug logs out of the kernel.
Indeed, but it will avoid corrupting the system.
> This only > turned up whilst debugging the controller, I got the timeout clock > calculation wrong and thus ended up timing out pretty much all the > CMD25s and seeing this problem. >
Just because you had to provoke it doesn't mean it won't appear under "normal" circumstances for others.
Until this problem is fully understood I think DMA should be turned off (or possibly needs to be explicitly forced on using Kconfig or a module parameter).
Do you have any contacts at Samsung that can help out here?
Rgds -- -- Pierre Ossman
Linux kernel, MMC maintainer http://www.kernel.org rdesktop, core developer http://www.rdesktop.org
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