Each packet is numbered and we stop after burst of 4096 packet of on the first missing packet. the first uint32_t will contain the current packet number and the second uint32_t will contain the number of packet to send. All packets have the same size (64 bytes). Our USB device work in full speed (USB 1.1) and follow the HID protocol. This debug protocol is very simple the Raspberry will send one packet of 64 bytes, then the device will start a burst of USB transaction. We have create an specific firmware illustrate the problem. We produce USB device and have found that we often get missing packet. We have found a serious issue on the raspberry PI USB stack (or at last the HID USB stack). this mean that the USB Host controller of the raspberry Pi as correctly received and ack the missing USB packet.Our conclusion is that or the libusb or the linux kernel drop some packets and do not raise any error. We have analyse the transfer with and USB analyser and ALL packets are correctly transmitted over the wire (no bus reset, no invalid packet, the USB host ack all packet).
USB congestion:our devices work in full-speed (USB 1.1 12 Mbit/s) and transmit at max 1 packet of 64 bytes each frame (64 Kb/s). More precisely there seems that there is some packet loss:
#Wxtoimg raspberry pi drivers
The main theory circulating on the net states that usb related issues (which can affect wi-fi dongles transfer, keyboard and mouse imputs etc etc) are due to some drivers problems which manifestates themselfs under heavy stress of usb\ethernet pathways, in conjunction and in some cases alone.
#Wxtoimg raspberry pi driver
I do really think this is related to an driver issue of the Soc controlling both ethernet and USB. In order to avoi resampling (you remember Audiophilia Hysterica obliges you to think resampling is evil?) I get audio stuttering, especially with flac with samplerate higher than redbook standards . I’m also having problems with RaspyFI, when i comment out the line That fixed all the buffering issues and makes the Pi read the shares much, much faster.
#Wxtoimg raspberry pi 1080p
I used to have the 1080p videos buffering all the time, but I fixed by switching my shares from Samba to NFS, using Hanewin NFS Server. I’m experiencing audio stutter while playing movies via the Raspberry Pi to the TV. Unfortunately there are some problems with audio stuttering and pop up clicking noises. One of the main concerns of folks who bought the Pi is to use it a media player – streamer – server, using USB Audio.
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