Re: [Linaro-mm-sig] Memory region attribute bits and multiple mappings

On Tue, Apr 19 2011, Rebecca Schultz Zavin wrote:

Until recently the dma api in the kernel was doing it too.  Apparently it's related to speculative prefetching, so as far as my understand goes, not an issue on Cortex-A8 where the feature isn't present.  However, there have been a couple of cases of data corruption due to it on A9.  It's also possible that the architecture licensee's implementations -- like the qualcomm snapdragons -- don't actually have a bug when this occurs.  I'm trying to collect the info on exactly which exhibit a problem.  Be aware though, it's a race condition, just because you never saw it doesn't mean you couldn't have.

Newer Qualcomm cores will have a problem with this as well.

David