Date: Mon, 6 Mar 2017 11:47:59 +0100 From: Markus Rechberger <mrechberger@gmail.com> To: Hans Petter Selasky <hps@selasky.org> Cc: freebsd-multimedia@freebsd.org Subject: Re: What is wrong with FreeBSD and USB Support Message-ID: <CA%2BO4pC%2BG=RBqbD=Ce3yy6rq-nUScJEd_G_D8NVpkapt8uGWd7w@mail.gmail.com> In-Reply-To: <9f51e1b1-d5df-afd3-f289-3bc55e417b5a@selasky.org> References: <CA%2BO4pCK4%2B1rE5ft4Boy_3xPdCxK31UtTQ2BYpnBUn5jxZr%2Bz_g@mail.gmail.com> <CA%2BO4pCJr5Bq-sgjzvZQB-mFRT6x7Tp3psga6f__V9Ag-=v-mhw@mail.gmail.com> <CA%2BO4pC%2Bf5xzOjENKSJu_sQeaiN3XL3WiTcRQvm4vVweQ71Xtrg@mail.gmail.com> <CA%2BO4pC%2B1t67ODF7bkyVhcojXTLnFkS28RbFAc%2Be-tjNncogMAQ@mail.gmail.com> <17db8b5b-9983-2ead-5c1d-960022afb1f6@selasky.org> <CA%2BO4pCLqORoQFT3cpfzLvor1HyQcP0Pr1CQq7QJM_9r=rTspdg@mail.gmail.com> <9f51e1b1-d5df-afd3-f289-3bc55e417b5a@selasky.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Mar 6, 2017 at 11:41 AM, Hans Petter Selasky <hps@selasky.org> wrote: > On 03/06/17 11:37, Markus Rechberger wrote: >> >> Are you sure? As from some of my signal analyzer dumps I do think that >> all those systems support >> multiple transfers within one completion event. I always request >> multiple frames within one request on those systems and they complete >> at once. And they only complete once all the buffers are filled. > > > Yes, I'm 100% sure. If you look at their APIs you will have to submit > individual jobs as a URB in Linux. If you want to send 128 x 333 bytes as > 333 byte sized USB HighSpeed BULK packets, then Linux/MacOS and Windows > force you to generate 128 URBs/Jobs to send the 128 packets. In FreeBSD a > single USB transfers can send 128x 333 bytes. Only in the case where you > send full-sized packets having an optional short-sized packet in the end, > Linux/MacOS and Windows allows you to accumulate them into a single > completion event. > Unless we're talking about something different here I'm always generating single 15k (or bigger) requests with Linux and request them at once. I do not have to generate N 512byte URBs to request 15k. And the 15k (or bigger) only complete once they're fully filled. > --HPS
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CA%2BO4pC%2BG=RBqbD=Ce3yy6rq-nUScJEd_G_D8NVpkapt8uGWd7w>