Date: Tue, 27 May 2014 14:06:24 +0000 (UTC) From: Scott Long <scottl@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r266745 - head/sys/x86/x86 Message-ID: <201405271406.s4RE6OBw028713@svn.freebsd.org>
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Author: scottl Date: Tue May 27 14:06:23 2014 New Revision: 266745 URL: http://svnweb.freebsd.org/changeset/base/266745 Log: Revert r266481. It was based on faulty analysis of the problem. A correct fix is forthcoming. Obtained from: Netflix, Inc. Modified: head/sys/x86/x86/busdma_bounce.c Modified: head/sys/x86/x86/busdma_bounce.c ============================================================================== --- head/sys/x86/x86/busdma_bounce.c Tue May 27 13:35:31 2014 (r266744) +++ head/sys/x86/x86/busdma_bounce.c Tue May 27 14:06:23 2014 (r266745) @@ -172,35 +172,12 @@ bounce_bus_dma_tag_create(bus_dma_tag_t newtag->map_count = 0; newtag->segments = NULL; - /* - * Bouncing might be needed if there's a filter. - * XXX Filters are likely broken as there's no way to - * guarantee that bounce pages will also satisfy the - * filter requirement. - */ if (parent != NULL && ((newtag->common.filter != NULL) || ((parent->common.flags & BUS_DMA_COULD_BOUNCE) != 0))) newtag->common.flags |= BUS_DMA_COULD_BOUNCE; - /* - * Bouncing might be needed if there's an upper memory - * restriction. - */ - if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem)) - newtag->common.flags |= BUS_DMA_COULD_BOUNCE; - - /* - * Bouncing might be needed if there's an alignment - * restriction that can't be satisfied by breaking up - * the segment. - * XXX Need to consider non-natural alignment. - * XXX Static allocations that tie to bus_dmamem_alloc() - * will likely pass this test and be penalized with - * the COULD_BOUNCE flag. Should probably have - * bus_dmamem_alloc() clear this flag. - */ - if ((newtag->common.nsegments <= 1) && - (newtag->common.alignment > 1)) + if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) || + newtag->common.alignment > 1) newtag->common.flags |= BUS_DMA_COULD_BOUNCE; if (((newtag->common.flags & BUS_DMA_COULD_BOUNCE) != 0) &&
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