linux-kernel - Re: [Patch] Increase USBFS Bulk Transfer size

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]

Message-ID: <CAHFNz9JE6FcBHyrSFEnnAjKsPtHWnYush-UMsg-tBLQfQ=Zwaw@mail.gmail.com>
Date:	Thu, 13 Oct 2011 15:04:39 +0530
From:	Manu Abraham <abraham.manu@...il.com>
To:	Markus Rechberger <mrechberger@...il.com>
Cc:	Greg KH <gregkh@...e.de>, Alan Stern <stern@...land.harvard.edu>,
	USB list <linux-usb@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [Patch] Increase USBFS Bulk Transfer size

> yes the PID is 0x1fff which are null packets over there, so those ones are okay.
> Main point is it works and it would even comply with certain HW specs (the other
> device points out about 256*188 bulk transfer buffer sizes.
>
> Now it would be the time for some people to open their eyes and get
> that patch in.

Call me dumb, but it still defies my logic why there would be stream
corruption with a smaller buffer size, if the driver is handling the
stream correctly.

I can probably imagine that there could be a likely chance, user space
would have to poll more often in case with smaller buffers, while
making it larger you increase the latency of the stream; that being a
double edged blade.

> The maximum transfer buffer size was derived from our other device which can
> do the flexible setting. According to the specification it is no magic value.

So, with your single device, if you were to make changes to some
"magical constants"; and tomorrow if someone wants to have
modifications again, what would you do ? If that change is a must,
maybe it should be configurable in some way, rather than having
another fixed magical number.

Regards,
Manu
--
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/