Date: Sun, 15 Aug 2010 21:11:59 +0200 From: Hans Petter Selasky <hselasky@c2i.net> To: Paul Thornton <prt@prt.org> Cc: freebsd-gnats-submit@freebsd.org, ed@freebsd.org, freebsd-usb@freebsd.org Subject: Re: usb/149675: uftdi doesn't react to break properly Message-ID: <201008152111.59671.hselasky@c2i.net> In-Reply-To: <4C6838A8.6040907@prt.org> References: <201008151947.04963.hselasky@c2i.net> <4C6838A8.6040907@prt.org>
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On Sunday 15 August 2010 20:57:44 Paul Thornton wrote: > Hi, > > Hans Petter Selasky wrote: > > I believe the following patch will fix your problem. Please apply and > > rebuild kernel / ucom module. > > That has made a dramatic difference - things now look much better. > Thank you very much for that. > > I'm still seeing a slight problem though. In my test setup, I have a PC > (Windows but that shouldn't matter!) running an appplication which > transmits a break followed by the 513 data bytes - and this repeats > continually at near line-rate at 250kbaud. > > Pre-patching, FreeBSD was unable to keep data byte 1 in location 1 at > all - it appeared randomly wherever it happened to be due to the lack of > break clearing the input buffer, and as the data dump of the buffer > refreshed, the values moved around as the breaks were turning up as datab. > > After I've applied the patch, it starts off well - data byte 1 is in > location 1, but every 5-10 seconds there is a shift by a byte suggesting > that an extra byte has been received. Is there any way that a break > could still be creeping in to the data stream periodically? > > Under Linux, the code runs properly and there is no movement of the data > bytes, so I'm reasonably confident that it isn't a bug of mine. > > Paul. I guess you will have to turn on ucom and uftdi debugging knobs under hw.usb.xxx to figure that out. USB is just forwarding what it gets from the hardware. --HPS
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