> -----Original Message----- > From: jung songtan [mailto:jungsongtan@xxxxxxxxx] > Sent: Tuesday, January 12, 2010 6:11 PM > To: Gupta, Ajay Kumar > Cc: linux-omap@xxxxxxxxxxxxxxx; jungsongtan > Subject: Re: Interval value set in RXINTERVAL register of MUSB? > > > Interval=2 for a low speed device means Host would issue > one IN tokens > > to get data on Interrupt IN pipe after every 2-frames > > (2ms or 16 micro frames). > > So, if the device always NAK, the host will always Tokenning IN ,and > occupy the End point and if the software did not stop it manually? > > Now, question is if another transaction depending on this Endpoint, it > will never occur if the Endpoint has been occupied, right? if so, how > to deal with Two or more interrupt transaction depending on One > Endpoint, any suggestion? What data are you using for Interrupt transfer? Do you really Need the interval to be =2 ? As device is NAKing it means, it's Not ready with data so you can try some larger interval value Say, =32 frames etc. > > > > We get NAK timeout error interrupt only in BULK transfers > case. Please > > See the details of RxInterval register. > > Yes, the datasheet shows that. > > 2010/1/12, Gupta, Ajay Kumar <ajay.gupta@xxxxxx>: > >> -----Original Message----- > >> From: jung songtan [mailto:jungsongtan@xxxxxxxxx] > >> Sent: Tuesday, January 12, 2010 3:22 PM > >> To: Gupta, Ajay Kumar; linux-omap@xxxxxxxxxxxxxxx > >> Subject: Interval value set in RXINTERVAL register of MUSB? > >> > >> Hi Ajay and expert, > >> > >> Can you correct me if my understanding has something wrong? > >> > >> > >> [Quote from usb 2.0 spec] > >> For full-/low-speed interrupt endpoints, the value of this field may > >> be from 1 to 255. > >> [Quote from usb 2.0 spec] > >> > >> So, If a Low speed Interrupt IN endpoint, the endpoint->interval = 0x2. > >> Now I want to request data from the endpoint, I set RXINTERVAL = 0x2, > >> and start to request the data.(All the related register set as bellow) > > > >> If my understanding is correctly, one NAKTIMEOUT interrupt will happen > >> if the device responses NAK longer time than 2 frame, rigtht? > > > > Interval=2 for a low speed device means Host would issue one IN tokens > > to get data on Interrupt IN pipe after every 2-frames > > (2ms or 16 micro frames). > > > > We get NAK timeout error interrupt only in BULK transfers case. Please > > See the details of RxInterval register. > > > > -Ajay > >> > >> But in my case did not, the host pending on the request for the data, > >> and no TIMEOUT interrupt happen , can you tell me, where I am missed > >> or where am I wrong? > >> > >> [Registers value ] > >> > >> RXCSR 0x20 > >> RXFUNCADDR 0x4 > >> RXHUBADDR 0x2 > >> RXHUBPORT 0x4 > >> RXMAXP 0x4 > >> RXINTERVAL 0x2 > >> > >> [Registers value ] > >> Thanks in advance, > >> > >> > >> > >> -- > >> K T Jung > > > > > -- > K T Jung -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
