Date: Wed, 15 Jan 2003 05:50:03 -0800 (PST) From: Henning Meier-Geinitz <henning@meier-geinitz.de> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/41281: USB scanning works only once Message-ID: <200301151350.h0FDo3DR046163@freefall.freebsd.org>
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The following reply was made to PR kern/41281; it has been noted by GNATS. From: Henning Meier-Geinitz <henning@meier-geinitz.de> To: Nate Lawson <nate@root.org> Cc: freebsd-bugs@FreeBSD.org, freebsd-gnats-submit@freebsd.org Subject: Re: kern/41281: USB scanning works only once Date: Wed, 15 Jan 2003 14:50:01 +0100 Hi, On Sun, Aug 25, 2002 at 12:48:29PM +0200, Henning Meier-Geinitz wrote: [Bug report about some Mustek USB scanners only working once in FreeBSD] After some more investigation and discussion with the Linux kernel USB people it seems to be clear now, that it's a hardware issue. The Mustek USB scanners that are based on the MA1017 chip (ScanExpress 1200 CU, 1200 CU Plus, 600 CU, 1200 UB), don't reset the data toggle. Never (but replugging/power-cycling). That means, whenever according to the USB spec the toggle is set to DATA0 (clear_halt, set_configuration, ...), it's only done on the host and the scanner doesn't do it. The result is that there is a 50% chance of lost packets. It doesn't happen with the Linux kernel scanner driver because that driver doesn't call any of the functions that reset the toggle during open/close. However, when reloading the scanner module the timeout problems also occurs. The only workaround seems to be don't do any togggle resetting after the first read/write access. I guess it's not worth the trouble if these scanners are the only device that exhibit this bug. Bye, Henning To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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