Messages in this thread | | | From | Oliver Neukum <> | Subject | Re: USB mass storage and ARM cache coherency | Date | Tue, 2 Feb 2010 14:08:51 +0100 |
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Am Dienstag, 2. Februar 2010 13:39:35 schrieb Catalin Marinas: > > For storage that is correct. But what about other sources of pages, > > for example iSCSI? > > In the iSCSI case, does the HCD driver write directly to a page cache > page? Or it just fills in network packets that are copied to page cache > pages by the iSCSI code (sorry, I'm not familiar with this part of the > kernel). If the latter, the cache flushing in the HCD driver would not > help and it needs to be done in the iSCSI code.
As far as I can tell iSCSI does a private copy. But I don't know how many methods to transfer code pages over USB exist. I'd say the conservative solution is to flush for everything but control transfers.
Regards Oliver
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