Date: Sun, 29 Jul 2012 08:52:33 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r238884 - head/sys/dev/ath Message-ID: <201207290852.q6T8qXNq028831@svn.freebsd.org>
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Author: adrian Date: Sun Jul 29 08:52:32 2012 New Revision: 238884 URL: http://svn.freebsd.org/changeset/base/238884 Log: Fix breakage introduced in r238824 - correctly calculate the descriptor wrapping. The previous code was only wrapping descriptor "block" boundaries rather than individual descriptors. It sounds equivalent but it isn't. r238824 changed the descriptor allocation to enforce that an individual descriptor doesn't wrap a 4KiB boundary rather than the whole block of descriptors. Eg, for TX descriptors, they're allocated in blocks of 10 descriptors for each ath_buf (for scatter/gather DMA.) Modified: head/sys/dev/ath/if_ath.c Modified: head/sys/dev/ath/if_ath.c ============================================================================== --- head/sys/dev/ath/if_ath.c Sun Jul 29 06:34:45 2012 (r238883) +++ head/sys/dev/ath/if_ath.c Sun Jul 29 08:52:32 2012 (r238884) @@ -2914,7 +2914,7 @@ ath_descdma_setup(struct ath_softc *sc, * in the descriptor. */ if (ATH_DESC_4KB_BOUND_CHECK(bf->bf_daddr, - dd->dd_descsize * ndesc)) { + dd->dd_descsize)) { /* Start at the next page */ ds += 0x1000 - (bf->bf_daddr & 0xFFF); bf->bf_desc = (struct ath_desc *) ds; @@ -2932,6 +2932,12 @@ ath_descdma_setup(struct ath_softc *sc, bf->bf_lastds = bf->bf_desc; /* Just an initial value */ TAILQ_INSERT_TAIL(head, bf, bf_list); } + + /* + * XXX TODO: ensure that ds doesn't overflow the descriptor + * allocation otherwise weird stuff will occur and crash your + * machine. + */ return 0; /* XXX this should likely just call ath_descdma_cleanup() */ fail3:
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