Date: Sun, 31 Aug 2014 05:40:48 +0300 From: atar <atar.yosef@gmail.com> To: Adrian Chadd <adrian@freebsd.org> Cc: "freebsd-wireless@freebsd.org" <freebsd-wireless@freebsd.org>, "freebsd-questions@freebsd.org" <freebsd-questions@freebsd.org> Subject: Re: TL-WN722N support on FreeBSD. Message-ID: <73C363A9-5608-4A2B-B9F3-D96E8BA93050@gmail.com> In-Reply-To: <CAJ-VmombJ8Ky8Lmj70YgUH7%2BfQkiwJQ9XyD7OqfkYfx7=OfdcA@mail.gmail.com> References: <C18F5819-A884-4A86-9FBA-FF7CEFF70695@gmail.com> <CAJ-VmombJ8Ky8Lmj70YgUH7%2BfQkiwJQ9XyD7OqfkYfx7=OfdcA@mail.gmail.com>
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Here's additional place where FreeBSD has lack of support: USB based printer= s. Here's a citation from the FreeBSD handbook (page no. 251): > USB interfaces, named for the Universal Serial Bus, can run at even faster= speeds than parallel or RS-232 serial interfaces. Cables are simple and che= ap. USB is superior to RS-232 Serial and to Parallel for printing, but it is= not as well supported under UNIX systems. A way to avoid this problem is to= purchase a printer that has both a USB interface and a Parallel interface, a= s many printers do. >=20 >> Hi, >>=20 >> The main issue is this: I really don't like the USB driver stuff in the k= ernel. >>=20 >> When I last checked, there was no clean example of a wifi or ethernet >> driver which handles all of the odd corner cases of things correctly. >> So you'd end up with things like taskqueues still running whilst the >> NIC had been pulled out, all sleeping on a wakeup that'll never come, >> or the ioctl path not really being locked the right way with the rest >> of the USB driver. >>=20 >> I started tinkering with a driver for the AR9170, but I still couldn't >> get the command handling side of things right. It's tricky because USB >> is effectively a network protocol, but all the drivers are written >> assuming register accesses are synchronous. So you end up having to >> craft some kind of command structure that handles sleeping for >> commands that it expects a response on from another USB endpoint (eg >> register reads), but not sleeping for commands that are asynchronous. >> I gave up because it became "non-fun." >>=20 >> So yeah. Almost all of the work is done in the atheros driver side of >> things. Heck, the AR9271 bits for the HAL are likely just an evenings >> worth of work for me. I just don't want to deal with the USB side of >> it. >>=20 >> I'm not being paid to do any of the wireless stuff in FreeBSD, so it >> has to clear the "is it fun" threshold. >>=20 >>=20 >> -a
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