Hi, > -----Original Message----- > From: Peter Chen [mailto:peter.chen@xxxxxxxxxxxxx] > Sent: Monday, August 31, 2015 7:59 AM > To: Punnaiah Choudary Kalluri > Cc: Nathan Sullivan; sundeep subbaraya; Subbaraya Sundeep Bhatta; > robh+dt@xxxxxxxxxx; pawel.moll@xxxxxxx; Mark Rutland; > ijc+devicetree@xxxxxxxxxxxxxx; Kumar Gala; Greg Kroah-Hartman; > devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux- > usb@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/2] usb: chipidea: add xilinx zynq platform data > > On Mon, Aug 31, 2015 at 09:01:51AM +0530, punnaiah choudary kalluri > wrote: > > 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. > > > > > > ok, so your platform can't use stream mode disabled. This is patch can be applied then. Thank you all. Sundeep > > -- > > Best Regards, > Peter Chen -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
