Date: Wed, 30 Aug 1995 00:38:46 -0500 From: Jon Loeliger <jdl@chrome.onramp.net> To: hackers@freebsd.org Subject: More ATAPI -- possible insight into probe problems...? Message-ID: <199508300538.AAA07671@chrome.onramp.net>
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Aha! Watch this:
Given:
controller wdc0 at isa? port "IO_WD1" bio irq 14 vector wdintr
disk wd0 at wdc0 drive 0
#disk wd1 at wdc0 drive 1
controller wdc1 at isa? port "IO_WD2" bio irq 15 vector wdintr
#disk wd2 at wdc1 drive 0
#disk wd3 at wdc1 drive 1
options ATAPI #Enable ATAPI support for IDE bus
device wcd0 #IDE CD-ROM
I see:
wd0: probe started
wd0: checking RW register on port 0x1f0 + 0x4
wd0: reseting
wd0: diagnosing
wd0: Error : 0x1
wdc0 at 0x1f0-0x1f7 irq 14 on isa
wdc0: unit 0 (wd0): <WDC AC31000H>
wd0: 1033MB (2116800 sectors), 2100 cyls, 16 heads, 63 S/T, 512 B/S
atapi0.1 at 0x1f0: attach called
atapi.1 at 0x1f0: identify not ready, status=1<check>
wd1: probe started
wd1: checking RW register on port 0x170 + 0x4
wdc1 not found at 0x170
Oh my! Let's peek at my highly superior wd.c:
static int
wdprobe(struct isa_device *dvp)
{
int unit = dvp->id_unit;
struct disk *du;
if (unit >= NWDC)
return (0);
#ifdef WDDEBUG_PROBE
printf("wd%d: probe started\n", unit);
#endif
du = malloc(sizeof *du, M_TEMP, M_NOWAIT);
if (du == NULL)
return (0);
bzero(du, sizeof *du);
du->dk_ctrlr = dvp->id_unit;
du->dk_port = dvp->id_iobase;
wdc_registerdev(dvp);
#ifdef WDDEBUG_PROBE
printf("wd%d: checking RW register on port 0x%x + 0x%x\n",
unit, du->dk_port, wd_cyl_lo);
#endif
/* check if we have registers that work */
outb(du->dk_port + wd_cyl_lo, 0xa5); /* wd_cyl_lo is read/write */
if (inb(du->dk_port + wd_cyl_lo) == 0xff) /* XXX too weak */
goto nodevice;
#ifdef WDDEBUG_PROBE
printf("wd%d: reseting\n", unit);
#endif
if (wdreset(du) != 0 && (DELAY(RECOVERYTIME), wdreset(du)) != 0)
goto nodevice;
So who can tell me any details about that lovely weak check for R/W
registers that appears to be failing for me? Simple things like:
- Is this a valid register for a CDROM drive too? Ie, is this check
tacitly assuming a hard disk beneath it?
- Is it subject to timing problems?
- It *claims* to be "too weak", however it appears to be too strong!
(Note also that I'd already bumped the TIMEOUT to 31000 to, I think,
meet spec. Didn't seem to help anywhere...)
Now I then did the obvious frob: totally *skip* this weak test.
This worked relatively nicely!
wd0: probe started
wd0: checking RW register on port 0x1f0 + 0x4
wd0: reseting
wd0: diagnosing
wd0: Error : 0x1
wdc0 at 0x1f0-0x1f7 irq 14 on isa
wdc0: unit 0 (wd0): <WDC AC31000H>
wd0: 1033MB (2116800 sectors), 2100 cyls, 16 heads, 63 S/T, 512 B/S
atapi0.1 at 0x1f0: attach called
atapi.1 at 0x1f0: identify not ready, status=1<check>
wd1: probe started
wd1: checking RW register on port 0x170 + 0x4
wd1: reseting
wd1: diagnosing
wd0: Error : 0x1
wdc1 at 0x170-0x177 irq 15 on isa
atapi1.0 at 0x170: attach called
wdc1: unit 0 (atapi): <NEC CD-ROM DRIVE:260>, removable, cmd16
wcd0: info 85-80-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-20-20-20-20-20-20-20-20-20-20-20-20-20-20-20-20-20-20-20-20-0-0-0-0-0-0-2e-34-33-32-20-20-20-20-4e-45-43-20-20-20-20-20-20-20-20-20-20-20-20-20-20-20-20-20-43-44-2d-52-4f-4d-20-44-52-49-56-45-3a-32-36-30-0-0-0-0-0-0-0-0-a-0-0-0-3-0-0-0-0-3-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-b4-0-b4-0-0-0-0-0-0-0-0-0-0-0
atapi1.0: req im 5a-0-2a-0-0-0-0-0-18-0-0-0-0-0-0-0 len=24
atapi1.0: start
atapi1.0: send cmd 5a-0-2a-0-0-0-0-0-18-0-0-0-0-0-0-0
atapi1.0: intr ireason=0x1, len=24, status=48<ready,drq>, error=0
atapi1.0: send cmd 5a-0-2a-0-0-0-0-0-18-0-0-0-0-0-0-0
atapi1.0: intr ireason=0x3, len=24, status=41<ready,check>, error=64<abort>
atapi1.1 at 0x170: attach called
atapi.1 at 0x170: no device
This is basically the same behaviour I was seeing when it was hanging
on the wdc0 controller. Note that slightly different behaviour was
observed as the ATAPI device was not found as the second device of
each of the two controllers.
So -- bottom line:
How 'bout that XXX weak register RW test?
How 'bout that double interrupt on cmd 5a?
Anyone?
jdl
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