2011/6/23 Jonathan Corbet <corbet@xxxxxxx>: > [Sorry, I'm just now recovering from one of those > total-loss-of-inbox-control episodes...] > > On Fri, 17 Jun 2011 11:11:33 +0800 > Kassey Lee <kassey1216@xxxxxxxxx> wrote: > >> the problem is: >> when we stop CCIC, and then switch to another format. >> at this stage, actually, CCIC DMA is not stopped until the >> transferring frame is done. this will cause system hang if we start >> CCIC again with another format. > > OK, I've never encountered that. The use case I'm coding for (OLPC) > doesn't involve a whole lot of format changes; generally they pick a > format for their record activity based on what works best on the display > side and stick with it. that is different with our stress test case. > >> from your logic, when stop DMA, you are test the EOF/SOF, so I >> wonder why you want to do this ? >> and is your test will stop CCIC and start CCIC frequently ? > > I wanted a way to know whether DMA was active or not; the idea was that an > SOF indicates that things are starting, EOF says that it's done. Are you > saying that there can be DMA active in the period after an EOF when the > subsequent SOF has not been received? this is OK if we are streaming data. but the point is CCIC DMA won't stop even we stop CCIC until the transferring frame is done. > > Thanks, > > jon > -- Best regards Kassey Application Processor Systems Engineering, Marvell Technology Group Ltd. Shanghai, China. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
