On Friday 23 January 2009, David Brownell wrote: > On Friday 23 January 2009, Philby John wrote: > > DM355 has 2 EDMA event queues and both > > are at present used by the MMC and the vdce driver respectively. So if > > you do want to use it for SPI, you must disable MMC or vdce and change > > the code in davinci_request_dma() to EVENTQ_0 or EVENTQ_1 > > Huh?? > > The whole point behind having a *QUEUE* is that each > TC can have a bunch of transfers ready to go. > > ISTR a "bunch" is up to sixteen -- in each queue.
... so, to be completely clear, it's no problem even if the VDCE driver has five transfers going, MMC has one, SPI and audio have two each. At most the queue depth would be 5 + 1 +2 + 2 == 10, which < 16. > SPI might use two transfers concurrently; ditto audio. > MMC would only use one at a time. > > Per TI docs, TC0 should be high priority for short > transfers, and TC1 should be low priority for bulk. > But those are "serving suggestions"; some systems > might want to use them differently. > > - Dave > > _______________________________________________ > Davinci-linux-open-source mailing list > [email protected] > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source > > _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
