Hi, On Wed, May 04, 2016 at 03:48:50PM +0000, Andrew Goodbody wrote: > Hi, > > I have been investigating communication issues with iPads. When the > system is busy it seems that the musb driver is silently dropping > occasional packets. I have a usbmon trace that does not show the > packet and I have a trace from a hardware USB analyser that does show > the packet. So the device is correctly sending the packet, it is even > being ACKed, but it is not passed up to the application. The packet is > a bulk transfer packet of 20 bytes. Can anyone please give me pointers > to where to go looking for the problem? The syslog shows nothing > relevant. What is the part number on the am3352 chip? What kernel version do you use? Is musb cppi dma enabled? If so, does the problem still happen when CPPI disabled? First try to turn on dynamic debug log in musb_host.c to check if musb receives the packet or not. Regards, -Bin. -- 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
