Date: Fri, 08 Nov 2002 12:21:26 -0800 From: Maksim Yevmenkin <myevmenk@exodus.net> To: current@freebsd.org Cc: Josef Karthauser <joe@tao.org.uk> Subject: Re: USB problem (Who owns USB code in -current?) Message-ID: <3DCC1CC6.AE6E74DF@exodus.net> References: <3DC6BD74.25097511@exodus.net>
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Dear Hackers, i'm replying to myself, because i think i might have found some more information on the problem. i would appreciate if any USB expert would care to comment on this. please take a look at http://www.geocities.com/m_evmenkin/usb/24505201.pdf and look for "USB Dribble" section. Let me quote it here <quote> 12. USB Dribble Issue: A USB receive packet with a bitstuff following the transmission of CRC, coupled with a dribble bit due to prop delays through cables and HUBs, may be incorrectly interpreted by the USB host controller state machine as a poorly formed EOP. Implication: The host controller response to this is a non-acknowledge with a CRC/Timeout status communicated to the software. If this condition persists, the error count associated with this packet will be exceeded and an interrupt can be generated to software. This will stall the USB device. Current software reports a device error to the user via a pop-up window. Another implication is that the installed base may have limited USB expandability via HUBs. Workaround: There are two possible workarounds. 1. Hardware: Attach the USB device into a USB port closer to the root hub. 2. Software: Detect the CRC/Timeout error and count exceeded and attempt to re-queue the packets while changing the length of the packets. Changing the length of the packets will change the CRC and thus will likely remove the combination of the two events causing the failure. Status: Fixed in B-0 stepping. Note: This erratum was carried over from the Intel® 82371EB (PIIX4E). </quote> Needless to say that i have Intel 82371AB/EB chip in my laptop *and* i'm getting CRCTO,TIMEOUT errors. all the dumps still available at http://www.geocities.com/m_evmenkin/usb/ could this be the problem? thanks, max Maksim Yevmenkin wrote: > > Dear Hackers, > > Who owns USB code in -current? I need an USB expert advice > on the FreeBSD specific USB problem. Basically whenever i > put my laptop into docking station and try to plug Bluetooth > USB dongle i get > > uhub1: device problem, disabling port 1 > > message. This problem *does not* exist when i try to > connect the USB dognle directly to the laptop. My current > theory is that extra USB hub in docking station somehow > makes the difference. I have attached few files that > might help. > > This problem is FreeBSD-specific and seems related to > Bluetooth USB dongles only. I have been contacted by other > people who have the same problem. I do not know what is so > special about Bluetooth USB dongles. USB mouse, for example, > works fine. Can it be power related? Both Windows and > Linux do not have this problem which makes me think that > there is something different about FreeBSD way of doing > things. > > Please advice. I will try to read USB spec, but if someone > could give me the right direction, that would be helpful. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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