Date: Wed, 19 Aug 2009 08:30:40 -0700 From: Sam Leffler <sam@errno.com> To: Rafal Jaworowski <raj@FreeBSD.org> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r196380 - head/sys/dev/usb Message-ID: <4A8C1AA0.20303@errno.com> In-Reply-To: <200908191439.n7JEd892057035@svn.freebsd.org> References: <200908191439.n7JEd892057035@svn.freebsd.org>
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Rafal Jaworowski wrote: > Author: raj > Date: Wed Aug 19 14:39:08 2009 > New Revision: 196380 > URL: http://svn.freebsd.org/changeset/base/196380 > > Log: > Fix USB cache sync operations for platforms with non-coherent DMA. > > - usb_pc_cpu_invalidate() is called between [consecutive] reads from a device, > so a sequence of BUS_DMASYNC_POSTREAD and _PREREAD should be used. Note we > cannot use or'ed shorthand ( _POSTREAD | _PREREAD) for BUS_DMASYNC flags, as > the low level bus dma sync operation is implementation dependent and we > cannot assume the required order of operations to be guaranteed. > > - usb_pc_cpu_flush() is called before writing to a device, so > BUS_DMASYNC_PREWRITE should be used. > > Submitted by: Grzegorz Bernacki > Reviewed by: HPS, arm@, usb@ ML > Tested by: HPS, Mike Tancsa > Approved by: re (kib) > Obtained from: Semihalf Is this different from the patch I tested on Gateworks 2358 boards which didn't completely resolve problems? Sam
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