Date: Mon, 24 May 2004 15:18:53 +0200 From: Peter.Weiss@Sun.com (Peter Weiss, Sun Microsystems, Germany) To: Ian Dowse <iedowse@maths.tcd.ie> Cc: current@freebsd.org Subject: Re: USB patch for better bus_dma and detachment support Message-ID: <xpxyu0y6j742.fsf@Sun.com> In-Reply-To: <200405232109.aa46210@salmon.maths.tcd.ie> (Ian Dowse's message of "Sun, 23 May 2004 21:09:01 %2B0100") References: <200405232109.aa46210@salmon.maths.tcd.ie>
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>>>>> "Ian" == Ian Dowse <iedowse@maths.tcd.ie> writes: Ian> In case anybody is interested in testing or helping with this, there's a Ian> patch at Ian> http://people.freebsd.org/~iedowse/usb.diff Ian> that attempts to begin addressing a number of problems with our current Ian> USB code: Ian> o All data buffers were allocated using bus_dma as physically Ian> contiguous memory. All transfers involve a memory copy to/from these Ian> contiguous buffers, and the contiguous memory is never freed. Use of Ian> these buffers is also inefficient, so low-memory systems tend to quickly Ian> run out of usable physical memory. Ian> o USB host controllers cannot be detached, so for example, unplugging a Ian> cardbus USB device will cause a crash. Ian> Neither of these issues is completely solved by the patch, but most I/O Ian> now avoids the need for contiguous buffers by using bus_dmamap_load() on Ian> the virtual buffer, and the system seems to survive the removal of a Ian> cardbus OHCI/EHCI controller, though memory is probably leaked. Ian> [...] Yes, the patch works, but does not fix the hotplugging of my optical usb mouse on my notebook. Unplugging is recognized, but no reaction seen if it's plugged in again Peter -- Peter Weiss / Peter.Weiss@germany.sun.com Sun Microsystems GmbH / Sonnenallee 1, D-85551 Kirchheim-Heimstetten (+49 89) 46008 2947 / mobil 0177/ 60 40 121
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