Messages in this thread | | | Date | Wed, 11 Jan 2012 21:35:00 +0800 | From | Shawn Guo <> | Subject | Re: [PATCH 6/6] dma/imx-sdma: check whether event_id0 < 32 when set event_mask |
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On Wed, Jan 11, 2012 at 09:09:11PM +0800, Richard Zhao wrote: > On Wed, Jan 11, 2012 at 09:16:17PM +0800, Shawn Guo wrote: > > On Wed, Jan 11, 2012 at 02:37:08PM +0800, Eric Miao wrote: > > > I think Richard has made the issue quite clear here, the original > > > > Yes, he has made it clear, but only after I asked for more comments, > > not with the empty commit message. > > > > > code does seem to have some problems even to me, who do not > > > understand the very details of the SDMA: > > > > > > - sdmac->event_mask0 = 1 << sdmac->event_id0; > > > - sdmac->event_mask1 = 1 << (sdmac->event_id0 - 32); > > > > > > 1. if sdmac->event_id0 >= 32, which will cause event_mask0 to be incorrect > > > 2. if sdmac->event_id < 32, sdmac->event_mask1 will be incorrect > > > > > My testing tells this is not the case. The event_mask0 will be 0 in > > case 1) and event_mask1 will be 0 in case 2), which is quite what we > > expect. And I do not believe you will see any functionality bug with > > the existing code. > Please see my mail mentioned "we shoud not let it depends on gcc's > behavior."
In this case, I would rather believe that the author is smart enough to write the code intentionally based on his good understanding on behavior of arm-gcc.
-- Regards, Shawn
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