On Tue, Aug 13, 2013 at 04:17:26PM -0500, Bin Liu wrote: > On Tue, Aug 13, 2013 at 4:13 PM, Felipe Balbi <balbi@xxxxxx> wrote: > > On Tue, Aug 13, 2013 at 03:41:01PM -0500, Bin Liu wrote: > >> On Tue, Aug 13, 2013 at 2:21 PM, Felipe Balbi <balbi@xxxxxx> wrote: > >> > On Tue, Aug 13, 2013 at 01:11:47PM -0500, Bin Liu wrote: > >> >> Sebastian, > >> >> > >> >> On Tue, Aug 13, 2013 at 12:38 PM, Sebastian Andrzej Siewior > >> >> <bigeasy@xxxxxxxxxxxxx> wrote: > >> >> > Since the musb-gadget code now calls the dma engine properly it is > >> >> > possible to enable it for the TX path in device mode. > >> >> > AM335x Advisory 1.0.13 says that we may lose the toggle bit on multiple > >> >> > RX transfers. There is a workaround in host mode but none in device mode > >> >> > and therefore RX transfers are disabled. > >> >> 1.0.13 only presents in PG1.0. It has been fixed in PG2.x. Maybe we > >> >> should check for silicon rev here? > >> > > >> > it would be quite difficult to check PG revision from this driver. It > >> > would have to be passed as a flag through DT or something similar. > >> > >> To make the code logic simple, I would think to ignore the rev check > >> and enable CPPI for RX in device mode. I think in theory the > >> controller in device mode will never hit on this hw bug. > > > > this patch is already in my branch going upstream. I think Sebastian has > > a point in leaving this disabled until he knows it's working fine. > > Ok. at least we have dma enabled for tx now ;) true, I'm sure Sebastian has plans on adding RX support, but only after he knows it's working fine ;-) -- balbi
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