Date: Tue, 24 Mar 98 22:48:12 EST From: luoqi@watermarkgroup.com (Luoqi Chen) To: freebsd-multimedia@FreeBSD.ORG, scottm@cs.ucla.edu Subject: Re: NEC 276 CDrom drive Message-ID: <9803250348.AA28812@watermarkgroup.com>
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> I brought this up on this list a few months ago, and now with a minor
> lull in my courses, I did some debugging. I'd been getting "unknown
> phase" errors and was told that this was due to latency in the controller.
>
> It's not. It's due to a strong predicate in atapi.c. I changed
>
> #define PHASE_COMPLETED (ARI_IN | ARI_CMD)
>
> to
>
> #define PHASE_COMPLETED (ARI_CMD)
>
> and the unknown phase (the more common problem for me) goes away.
> Apparently, the controller doesn't assert ARI_IN when the ATAPI_MODE_SENSE
> command is done.
>
> Question: Is this change to PHASE_COMPLETED, albeit a weaker predicate,
> safe? And can someone commit this change to -current?
You can't do this. According to spec, ARI_IN and ARI_CMD both have to be
asserted when data transfer is done.
I have a NEC 273/4.21 drive, and I saw the same message during bootup.
Signal timing for these NEC drives doesn't exactly follow the spec:
when data transfer is done, the drive should assert IO/CMD first, then
deassert ARQ and BSY, then assert INTRQ.
Try the following patch:
Index: atapi.c
===================================================================
RCS file: /fun/cvs/src/sys/i386/isa/atapi.c,v
retrieving revision 1.24
diff -u -r1.24 atapi.c
--- atapi.c 1998/03/01 18:57:27 1.24
+++ atapi.c 1998/03/24 07:48:05
@@ -711,7 +711,9 @@
{
u_char ireason;
u_short len, i;
+ int retry = 100;
+again:
if (atapi_wait (ata->port, 0) < 0) {
ac->result.status = inb (ata->port + AR_STATUS);
ac->result.error = inb (ata->port + AR_ERROR);
@@ -734,8 +736,13 @@
ac->result.status, ARS_BITS,
ac->result.error, AER_BITS);
}
- switch ((ireason & (ARI_CMD | ARI_IN)) | (ac->result.status & ARS_DRQ)) {
+ switch ((ireason & (ARI_CMD|ARI_IN)) | (ac->result.status & ARS_DRQ)) {
default:
+ /* we could be between phases for immediate requests */
+ if (!ac->callback && retry--) {
+ DELAY(10);
+ goto again;
+ }
printf ("atapi%d.%d: unknown phase\n", ata->ctrlr, ac->unit);
ac->result.code = RES_ERR;
break;
@@ -948,20 +955,13 @@
/* Send packet command. */
atapi_send_cmd (ata, ac);
- /* Wait for data i/o phase. */
- for (cnt=20000; cnt>0; --cnt)
- if (((inb (ata->port + AR_IREASON) & (ARI_CMD | ARI_IN)) |
- (inb (ata->port + AR_STATUS) & ARS_DRQ)) != PHASE_CMDOUT)
- break;
-
- /* Do all needed i/o. */
- while (atapi_io (ata, ac))
- /* Wait for DRQ deassert. */
+ do {
for (cnt=2000; cnt>0; --cnt) {
- if (! (inb (ata->port + AR_STATUS) & ARS_DRQ))
+ u_char s = inb(ata->port + AR_STATUS);
+ if ((s & (ARS_DRQ | ARS_BSY)) == ARS_BSY)
break;
- DELAY(10);
}
+ } while (atapi_io(ata, ac));
}
return (ac->result);
}
>
> -scooter
> --
> Scott Michel | In life, there are sheep and there are
> UCLA Computer Science | wolves.
> PhD Graduate Student | ... And I don't bleed ...
>
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-lq
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