> -----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 -- 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
