Date: Tue, 16 Mar 2010 16:46:19 +0100 From: Sebastian Huber <sebastian.huber@embedded-brains.de> To: freebsd-usb@freebsd.org Subject: How fast is the OHCI driver? Message-ID: <4B9FA7CB.70200@embedded-brains.de>
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Hi, I work with an ARM9 based system on a LPC3250 evaluation board from Phytec. It has an integrated OHCI USB controller from NXP. The vendor provides a Linux system for this board and with this system I can read with 1MByte/s from an USB stick (I can also read with 23MByte/s from this stick on another system with an EHCI controller). If I use the FreeBSD USB-stack (trunk revision 200101), then I can only achieve a read performance of 70kByte/s. Comparing the activity on the USB data lines with an oscilloscope of the two systems shows that on the Linux system the line is continuously busy while on the FreeBSD based system there are huge gaps of inactivity. Both systems operate with 12MHz. The FreeBSD based system is 65% of the time in the idle task, so it seems that it waits a lot for something. Has someone values from other FreeBSD based systems with an OHCI controller? Have a nice day! Sebastian Huber -- Sebastian Huber, embedded brains GmbH Address : Obere Lagerstr. 30, D-82178 Puchheim, Germany Phone : +49 89 18 90 80 79-6 Fax : +49 89 18 90 80 79-9 E-Mail : sebastian.huber@embedded-brains.de PGP : Public key available on request. Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
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