linux-kernel - Re: [PATCH 0/1] staging: Add firewire-serial driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 23 Oct 2012 20:41:11 +0200
From:	Stefan Richter <stefanr@...6.in-berlin.de>
To:	Peter Hurley <peter@...leysoftware.com>
Cc:	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	devel@...verdev.osuosl.org, linux1394-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org
Subject: Re: [PATCH 0/1] staging: Add firewire-serial driver

On Oct 23 Peter Hurley wrote:
> most controllers allow spillover into
> the portion of bus cycle assigned for sync tx (which is another 4Kbytes
> per 125us).

All controllers do so and are expected to do so.  Asynchronous traffic is
not supposed to depend on a cycle master being active.

> (Technical note: the actual total max for combined async
> and sync tx is 6144 bytes per 125us clock)

It depends on bus topology, transaction types, and more.  For a single-hop
S400 1394a bus (vulgo FireWire 400) I once calculated 44 MB/s bandwidth of
asynchronous unified write transactions:
http://marc.info/?l=linux1394-devel&m=109128028930225
That's at the physical layer; link layer and application layer performances
are less than that of course.
-- 
Stefan Richter
-=====-===-- =-=- =-===
http://arcgraph.de/sr/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/