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Do not report each pseudo-DMA overrun as a (soft) error.

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Add a small heuristic to converge on an acceptable threshold value.
This commit is contained in:
pk 1995-04-25 14:44:44 +00:00
parent 589f248bad
commit 64f2d35a0f
1 changed files with 40 additions and 11 deletions
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51
sys/arch/sparc/dev/fd.c
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@ -1,4 +1,4 @@
/* $NetBSD: fd.c,v 1.5 1995/04/13 20:24:36 pk Exp $ */
/* $NetBSD: fd.c,v 1.6 1995/04/25 14:44:44 pk Exp $ */
/*-
* Copyright (c) 1993, 1994, 1995 Charles Hannum.
@ -104,6 +104,7 @@ struct fdc_softc {
#define FDC_NEEDHEADSETTLE 0x02
#define FDC_EIS 0x04
int sc_errors; /* number of retries so far */
int sc_overruns; /* number of DMA overruns */
int sc_cfg; /* current configuration */
struct fdcio sc_io;
#define sc_reg_msr sc_io.fdcio_reg_msr
@ -362,9 +363,9 @@ fdcattach(parent, self, aux)
/*
* Configure controller; enable FIFO, Implied seek, no POLL mode?.
* Note: CFG_EFIFO is active-low, initial threshold value: 0
* Note: CFG_EFIFO is active-low, initial threshold value: 8
*/
fdc->sc_cfg = CFG_EIS|/*CFG_EFIFO|*/CFG_POLL|(0 & CFG_THRHLD_MASK);
fdc->sc_cfg = CFG_EIS|/*CFG_EFIFO|*/CFG_POLL|(8 & CFG_THRHLD_MASK);
fdconf(fdc);
if (fdc->sc_flags & FDC_82077) {
@ -1150,17 +1151,28 @@ loop:
fd->sc_blkno, fd->sc_nblks, fdc->sc_tc);
}
#endif
if (st1 & ST1_OVERRUN) {
/* Try a higher threshold */
if (fdc->sc_nstat == 7 &&
(st1 & ST1_OVERRUN) == ST1_OVERRUN) {
/*
* Silently retry overruns if no other
* error bit is set. Adjust threshold.
*/
int thr = fdc->sc_cfg & CFG_THRHLD_MASK;
fdc->sc_cfg &= ~CFG_THRHLD_MASK;
if (thr < 15) thr++;
fdc->sc_cfg |= (thr & CFG_THRHLD_MASK);
if (thr < 15) {
thr++;
fdc->sc_cfg &= ~CFG_THRHLD_MASK;
fdc->sc_cfg |= (thr & CFG_THRHLD_MASK);
#ifdef FD_DEBUG
if (fdc_debug)
printf("fdc: %d -> threshold\n", thr);
if (fdc_debug)
printf("fdc: %d -> threshold\n", thr);
#endif
fdconf(fdc);
fdconf(fdc);
fdc->sc_state = DOIO;
fdc->sc_overruns = 0;
}
if (++fdc->sc_overruns < 3)
goto loop;
}
fdcretry(fdc);
goto loop;
@ -1170,6 +1182,21 @@ loop:
fd->sc_skip / FDC_BSIZE, (struct disklabel *)NULL);
printf("\n");
fdc->sc_errors = 0;
} else {
if (--fdc->sc_overruns < -5) {
int thr = fdc->sc_cfg & CFG_THRHLD_MASK;
if (thr > 0) {
thr--;
fdc->sc_cfg &= ~CFG_THRHLD_MASK;
fdc->sc_cfg |= (thr & CFG_THRHLD_MASK);
#ifdef FD_DEBUG
if (fdc_debug)
printf("fdc: %d -> threshold\n", thr);
#endif
fdconf(fdc);
}
fdc->sc_overruns = 0;
}
}
fd->sc_blkno += fd->sc_nblks;
fd->sc_skip += fd->sc_nbytes;
@ -1258,6 +1285,8 @@ fdcretry(fdc)
fd = fdc->sc_drives.tqh_first;
bp = fd->sc_q.b_actf;
fdc->sc_overruns = 0;
switch (fdc->sc_errors) {
case 0:
/* try again */