Hi, On Tue, Nov 20, 2018 at 09:28:37AM +0200, Peter Ujfalusi wrote: > On 19/11/2018 20.46, Aaro Koskinen wrote: > > On Mon, Nov 19, 2018 at 12:40:40PM +0200, Peter Ujfalusi wrote: > >> When the channel is configured for slave operation the LCH_TYPE needs to be > >> set to LCh-P. For memcpy channels the LCH_TYPE must be set to LCh-2D. > >> > >> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx> > > > > I don't have the documentation, but based on what omap_udc driver (still > > using the legacy OMAP DMA API) does this seems to be correct. > > They are hard to fine, true. From the omap1710 TRM: > > Logical channel types (LCh types) supported are: > - LCh-2D for nonsynchronized transfers (memory transfers, 1D and 2D) > - LCh-P for synchronized transfers (mostly peripheral transfers) > - LCh-PD similar to LCh-P but runs on a dedicated physical channel > - LCh-G for graphical transfers/operations > - LCh-D for display transfers (I found a public document "OMAP5912 Multimedia Processor Direct Memory Access (DMA) Support Reference Guide", documenting these; easy to confuse with "OMAP5910 Dual-Core Processor System DMA Controller Reference Guide".) > Looking at other part it looks like hat LCH-2D channel mode can happily > service a peripheral. LCH-P supports the same features as LCH-2D, but it > lacks support for Single/Double-indexed addressing mode on the > peripheral port side. > > So, this patch might not be needed at all. Can you test the omap_udc > with s/OMAP_DMA_LCH_P/OMAP_DMA_LCH_2D > > If USB works, then we can just drop this patch. Unfortunately omap_udc does not seem to work at all anymore with DMA on my 770 setup. :-( I had switched to PIO mode in 2015 since the WARNs about legacy DMA API were too annoying and flooding the console. And now that I tried using DMA again with g_ether, it doesn't work anymore. The device get's recognized on host side, but no traffic goes through. Switching back to PIO makes it to work again. A.
