Do not mark target/LUN busy until we commit to working with it,
after the check for reselections. (From Matthias Pfaller, PR 2105) Also improve the selection code WRT concurrent reselection.
This commit is contained in:
gwr
parent
89179744bd
commit
a19a024e59
|
|
@ -1,4 +1,4 @@
|
|||
/* $NetBSD: ncr5380sbc.c,v 1.3 1996/02/10 00:11:48 christos Exp $ */
|
||||
/* $NetBSD: ncr5380sbc.c,v 1.4 1996/02/22 03:10:47 gwr Exp $ */
|
||||
|
||||
/*
|
||||
* Copyright (c) 1995 David Jones, Gordon W. Ross
|
||||
|
|
@ -838,10 +838,16 @@ next_job:
|
|||
target = sc->sc_ring[i].sr_target;
|
||||
lun = sc->sc_ring[i].sr_lun;
|
||||
if (sc->sc_matrix[target][lun] == NULL) {
|
||||
sc->sc_matrix[target][lun] =
|
||||
sr = &sc->sc_ring[i];
|
||||
sc->sc_rr = i;
|
||||
break;
|
||||
/*
|
||||
* Do not mark the target/LUN busy yet,
|
||||
* because reselect may cause some other
|
||||
* job to become the current one, so we
|
||||
* might not actually start this job.
|
||||
* Instead, set sc_matrix later on.
|
||||
*/
|
||||
sc->sc_rr = i;
|
||||
sr = &sc->sc_ring[i];
|
||||
break;
|
||||
}
|
||||
}
|
||||
i++;
|
||||
|
|
@ -883,7 +889,8 @@ next_job:
|
|||
goto have_nexus;
|
||||
}
|
||||
|
||||
/* Normal selection result */
|
||||
/* Normal selection result. Target/LUN is now busy. */
|
||||
sc->sc_matrix[target][lun] = sr;
|
||||
sc->sc_current = sr; /* connected */
|
||||
xs = sr->sr_xs;
|
||||
|
||||
|
|
@ -1265,7 +1272,7 @@ ncr5380_select(sc, sr)
|
|||
struct ncr5380_softc *sc;
|
||||
struct sci_req *sr;
|
||||
{
|
||||
int timo;
|
||||
int timo, s;
|
||||
u_char bus, data, icmd;
|
||||
|
||||
/* Check for reselect */
|
||||
|
|
@ -1296,20 +1303,29 @@ ncr5380_select(sc, sr)
|
|||
* We then wait for one arbitration delay (2.2uS) and
|
||||
* check the ICMD_LST bit, which will be set if some
|
||||
* other target drives SEL during arbitration.
|
||||
*
|
||||
* There is a time-critical section during the period
|
||||
* after we enter arbitration up until we assert SEL.
|
||||
* Avoid long interrupts during this period.
|
||||
*/
|
||||
s = splimp(); /* XXX: Begin time-critical section */
|
||||
|
||||
*(sc->sci_odata) = 0x80; /* OUR_ID */
|
||||
*(sc->sci_mode) = SCI_MODE_ARB;
|
||||
|
||||
/* Wait for ICMD_AIP. */
|
||||
timo = ncr5380_wait_req_timo;
|
||||
timo = 10; /* 20 uSec is pleanty. */
|
||||
for (;;) {
|
||||
if (*(sc->sci_icmd) & SCI_ICMD_AIP)
|
||||
break;
|
||||
if (--timo <= 0) {
|
||||
/* Did not see any "bus free" period. */
|
||||
*sc->sci_mode = 0;
|
||||
/*
|
||||
* Did not see any "bus free" period.
|
||||
* The usual reason is a reselection,
|
||||
* so treat this as arbitration loss.
|
||||
*/
|
||||
NCR_TRACE("select: bus busy, rc=%d\n", XS_BUSY);
|
||||
return XS_BUSY;
|
||||
goto lost_arb;
|
||||
}
|
||||
delay(2);
|
||||
}
|
||||
|
|
@ -1322,10 +1338,8 @@ ncr5380_select(sc, sr)
|
|||
/* Check for ICMD_LST */
|
||||
if (*(sc->sci_icmd) & SCI_ICMD_LST) {
|
||||
/* Some other target asserted SEL. */
|
||||
*sc->sci_mode = 0;
|
||||
NCR_TRACE("select: lost one, rc=%d\n", XS_BUSY);
|
||||
ncr5380_reselect(sc); /* XXX */
|
||||
return XS_BUSY;
|
||||
goto lost_arb;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -1335,7 +1349,7 @@ ncr5380_select(sc, sr)
|
|||
* We can now declare victory by asserting SEL.
|
||||
*
|
||||
* Note that the 5380 is asserting BSY because we
|
||||
* asked it to do arbitration. We will now hold
|
||||
* have entered arbitration mode. We will now hold
|
||||
* BSY directly so we can turn off ARB mode.
|
||||
*/
|
||||
icmd = (SCI_ICMD_BSY | SCI_ICMD_SEL);
|
||||
|
|
@ -1349,27 +1363,41 @@ ncr5380_select(sc, sr)
|
|||
*/
|
||||
delay(2);
|
||||
|
||||
#if 1
|
||||
/*
|
||||
* XXX: Check one last time to see if we really
|
||||
* XXX: did win arbitration. (too paranoid?)
|
||||
* Check one last time to see if we really did
|
||||
* win arbitration. This might only happen if
|
||||
* there can be a higher selection ID than ours.
|
||||
* Keep this code for reference anyway...
|
||||
*/
|
||||
if (*(sc->sci_icmd) & SCI_ICMD_LST) {
|
||||
/* Some other target asserted SEL. */
|
||||
NCR_TRACE("select: lost two, rc=%d\n", XS_BUSY);
|
||||
|
||||
lost_arb:
|
||||
*sc->sci_icmd = 0;
|
||||
*sc->sci_mode = 0;
|
||||
NCR_TRACE("select: lost two, rc=%d\n", XS_BUSY);
|
||||
|
||||
splx(s); /* XXX: End of time-critical section. */
|
||||
|
||||
/*
|
||||
* When we lose arbitration, it usually means
|
||||
* there is a target trying to reselect us.
|
||||
*/
|
||||
ncr5380_reselect(sc);
|
||||
return XS_BUSY;
|
||||
}
|
||||
#endif
|
||||
|
||||
/* Leave ARB mode Now that we drive BSY+SEL */
|
||||
*sc->sci_mode = 0;
|
||||
*sc->sci_sel_enb = 0;
|
||||
|
||||
splx(s); /* XXX: End of time-critical section. */
|
||||
|
||||
/*
|
||||
* Arbitration is complete. Now do selection:
|
||||
* Drive the data bus with the ID bits for both
|
||||
* the host and target. Also set ATN now, to
|
||||
* ask the target for a messgae out phase.
|
||||
* ask the target for a message out phase.
|
||||
*/
|
||||
data = 0x80 | (1 << sr->sr_target);
|
||||
*(sc->sci_odata) = data;
|
||||
|
|
|
|||
Loading…
Reference in New Issue