On Wed, Mar 27, 2013 at 6:43 PM, B, Ravi <ravib...@ti.com> wrote: > Hi > > I am observing issue while streaming video from usb camera connected to host > controller based on mentor graphics. The issue is root caused that there are > huge SOF gaps seen between the two isochronous IN token issued by host > controller. This is due to fact, significant amount of time is spent in uvc > callback function handler. Due to this next request programmed is delayed > leads to this failure of video streaming. I have measured time taken by uvc > callback function is in range minimum of 11 microsecond to maximum of 3318 > microsecond. Looks like callback handler doing
If you are playing ARM and I remember correctly, it is quite slow to read coherent memory from CPU, but writing is OK because of store buffer. Thanks, -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
