diff options
| author | gibbs <gibbs@FreeBSD.org> | 1997-04-24 16:52:18 +0000 |
|---|---|---|
| committer | gibbs <gibbs@FreeBSD.org> | 1997-04-24 16:52:18 +0000 |
| commit | 3ca5733308e4f7acc28a4cb8b28cbb0ade9573c4 (patch) | |
| tree | 4124b8ff69ba360421a93675b0bc71e9cbd33383 | |
| parent | 96ee89db8ac466642c97066df622847f516e2f19 (diff) | |
| download | FreeBSD-src-3ca5733308e4f7acc28a4cb8b28cbb0ade9573c4.zip FreeBSD-src-3ca5733308e4f7acc28a4cb8b28cbb0ade9573c4.tar.gz | |
The following scenario would result in a bogus residual being reported
if SCB Paging was enabled:
disconnect with more data to transfer
disconnected SCB gets paged out
target reconnects so we page SCB back in
target completes transfer so residual is 0
target disconnects
SCB gets reused but not paged out since the residual is 0 (optimization)
target reconnects so we page the SCB back in
we report a residual because of stale residual information.
The fix for this is to set a flag that forces the SCB to be paged back
up to the host if we page in an SCB with a residual
Pointed out by: Doug Ledford <dledford@dialnet.net>
| -rw-r--r-- | sys/dev/aic7xxx/aic7xxx.reg | 4 | ||||
| -rw-r--r-- | sys/dev/aic7xxx/aic7xxx.seq | 7 |
2 files changed, 8 insertions, 3 deletions
diff --git a/sys/dev/aic7xxx/aic7xxx.reg b/sys/dev/aic7xxx/aic7xxx.reg index ac45ec2..2bb3184 100644 --- a/sys/dev/aic7xxx/aic7xxx.reg +++ b/sys/dev/aic7xxx/aic7xxx.reg @@ -28,7 +28,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: aic7xxx.reg,v 1.1 1997/03/16 07:08:11 gibbs Exp $ + * $Id: aic7xxx.reg,v 1.2 1997/04/14 02:26:56 gibbs Exp $ */ /* @@ -764,7 +764,7 @@ scb { bit MK_MESSAGE 0x80 bit DISCENB 0x40 bit TAG_ENB 0x20 - bit SPLIT_SG 0x10 + bit MUST_DMAUP_SCB 0x10 bit ABORT_SCB 0x08 bit DISCONNECTED 0x04 mask SCB_TAG_TYPE 0x03 diff --git a/sys/dev/aic7xxx/aic7xxx.seq b/sys/dev/aic7xxx/aic7xxx.seq index 0a64425..f6cfe81 100644 --- a/sys/dev/aic7xxx/aic7xxx.seq +++ b/sys/dev/aic7xxx/aic7xxx.seq @@ -37,7 +37,7 @@ *OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF *SUCH DAMAGE. * - * $Id: aic7xxx.seq,v 1.71 1997/04/14 02:26:59 gibbs Exp $ + * $Id: aic7xxx.seq,v 1.72 1997/04/18 16:31:55 gibbs Exp $ * *-M************************************************************************/ @@ -980,6 +980,8 @@ findSCB_loop: mov ALLZEROS call get_free_or_disc_scb; mvi DMAPARAMS, HDMAEN|DIRECTION|FIFORESET; mov ARG_1 call dma_scb; + test SCB_RESID_SGCNT, 0xff jz . + 2; + or SCB_CONTROL, MUST_DMAUP_SCB; test SCB_CONTROL, ABORT_SCB jz return; find_error: mvi SINDEX, SCB_LIST_NULL ret; @@ -1117,6 +1119,9 @@ dequeue_disc_scb: * and we have to send this SCB back up to the kernel so that the * saved data pointers and residual information isn't lost. */ + test SCB_CONTROL, MUST_DMAUP_SCB jz . + 3; + and SCB_CONTROL, ~MUST_DMAUP_SCB; + jmp dma_up_scb; test SCB_RESID_SGCNT,0xff jnz dma_up_scb; cmp SCB_LINKED_NEXT, SCB_LIST_NULL je unlink_disc_scb; dma_up_scb: |
