Re: Question regarding CDC NCM and VNC performance issue

[Oliver Neukum <oneukum@suse.com>]

On 05.12.23 21:14, Hiago De Franco wrote:
> From: Hiago De Franco <hiago.franco@toradex.com>
> 
> Hi Oliver,
> 
> Following up on your initial email, I found that adjusting the NTB size
> successfully resolved the problem on both Linux and Windows. The VNC
> client is now operating with speed and stability after dividing the
> package size by 8.

OK, that indicates that your performance is bad because your VNC client
was only partially filling the buffers, which caused most of your packets
to be transmitted only upon a timeout.

At least this is my working hypothesis.

> I know that altering the NTB size is not the correct solution, please
> consider the attached patch as an explanation, but the assumption that the
> issue may be related to an accumulation of small packages, causing delays
> in fulfilling the 16KB requirement, seems related.

Before we proceed, however, your patch raises a fundamental question:
Are we talking about gadget or host mode here?
Could you please describe your setup in detail?

	Regards
		Oliver