On Fri, Aug 28, 2015 at 09:30:12AM +0800, Peter Chen wrote: > On Thu, Aug 27, 2015 at 09:33:07AM -0500, Nathan Sullivan wrote: > > On Thu, Aug 27, 2015 at 01:11:30PM +0530, punnaiah choudary kalluri wrote: > > > Hi, > > > > > > On Thu, Aug 27, 2015 at 10:03 AM, Peter Chen <peter.chen@xxxxxxxxxxxxx> wrote: > > > > On Thu, Aug 27, 2015 at 10:59:22AM +0530, sundeep subbaraya wrote: > > > >> Hi, > > > >> > > > >> > > > >> On Wed, Aug 26, 2015 at 8:57 PM, Nathan Sullivan <nathan.sullivan@xxxxxx> wrote: > > > >> > The Xilinx Zynq udc does not need the CI_HDRC_DISABLE_STREAMING flag, > > > >> > unlike the default platform data. Add platform data specific to the > > > >> > Zynq udc. > > > >> > > > > >> > Based on a patch by the same name from the Xilinx vendor tree. > > > >> > > > >> I am that Xilinx guy who sent this patch :). It is in Xilinx tree as > > > >> temporary fix and > > > >> I did not debug further why UDC works only when streaming is enabled. > > > >> Probably this is right time to post my question here. > > > >> I was expecting like: > > > >> Streaming disabled - both low bandwidth and high bandwidth systems > > > >> should work fine > > > >> Streaming enabled - only for high bandwidth systems > > > >> but this is not the case, Zynq UDC works only when Streaming is enabled. > > > >> Please correct me if I am wrong. > > > > > > > > You are right, stream mode disabled should work at anytime. > > > > It is so strange why zynq UDC only works when stream mode is enabled. > > > > > > I am referring the section 8.5.2 in Synopsys usb 2.0 HS controllervDoc 2.20a, > > > this is what it says about SDIS (streaming mode disable option) > > > > > > Before activating this mode, the user must check if the TX latency > > > buffers per endpoint are able to > > > accommodate at least one entire maximum size packet. The RX buffer > > > size must, at least, double the TX > > > buffer size per endpoint. To optimize the stream disable performance, > > > system bus burst must be set as high > > > as possible. > > > When the stream disable mode is used, the burst size (VUSB_HS_RX_BURST > > > and VUSB_HS_TX_BURST) > > > must be a integer sub-multiple of the latency buffer size > > > (VUSB_HS_RX_DEPTH for RX buffer and > > > VUSB_HS_TX_CHAN for the TX buffer). If this is not respected the > > > controller will not work properly in stream > > > disable mode. > > > The stream disable mode should just be used in situations where the > > > available system bandwidth is low or the > > > system bus access latency is high, in order to avoid underruns and > > > overruns in the latency buffers. This works > > > for all types of endpoints, except for ISO endpoints. > > > Such a system can't ensure the real time support that the ISO > > > endpoints require, so the ISO endpoints are not > > > supported when the SDIS bit is set. > > > > > > Definitely we need to root cause why disable streaming mode is not > > > working for zynq but from controller spec > > > point of view it is possible that controller not work properly in > > > stream disable mode. > > > > > > Regards, > > > Punnaiah > > > > > > > Maybe the burst size isn't set correctly by default? It does say the controller > > won't work correctly with stream disable set and an invalid burst size. Looks > > like TX and RX burst both default to 16, per the Zynq manual. > > > > With the stream disable bit set, the behvior we see on our hardware is > > that priming just stops, with an outstanding transfer in memory marked > > active in the status field by the controller. This happens at random, even > > when doing single transfers at a time like with g_ether set to have a queue > > size of 1. With SDIS clear everything works great. Given that the Zynq is not > > bandwidth constrained, it seems like SDIS clear should be the default. > > > > I suspect the possible reason is the tx buffer for each endpoint is > small (<=512 bytes), so it can't copy one packet (assume max packet size > for bulk) to tx buffer, then the prime can't be finished. > > Would you help to dump the registers HWTXBUF ($BASE + 0x10) and DCCPARAMS > ($BASE + 124)? > > tx buffer size = ((2 ^ HWTXBUF.VUSB_HS_TX_ADD) / DCCPARAMS.DEN) * > (DWORD_PER_BYTES) > > DWORD_PER_BYTES is 4 > > -- > > Best Regards, > Peter Chen HWTXBUF is 0x80060A10, DCCPARAMS is 0xE0003124. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
