On Mon, Aug 31, 2015 at 6:10 AM, Peter Chen <peter.chen@xxxxxxxxxxxxx> wrote: > On Fri, Aug 28, 2015 at 09:42:56AM -0500, Nathan Sullivan wrote: >> 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. > > Are you sure you read correct address? Your DCCPARAMS means > it is host capable, but not device capable. HWTXBUF is 0x8060A10 DCCPARAMS is 0x0000018C VUSB_HS_TX_ADD - 0xA DEN - 0xC >From the above formula tx buffer size is 341.33 bytes. Regards, Punnaiah > > -- > > Best Regards, > Peter Chen > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- 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
