Re: kern/56982: mutex error (locking against myself) in wdc(4) NOIRQcase?

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

The following reply was made to PR kern/56982; it has been noted by GNATS.

From: Rin Okuyama <rokuyama.rk%gmail.com@localhost>
To: Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>
Cc: gnats-bugs%netbsd.org@localhost, riastradh%NetBSD.org@localhost, kern-bug-people%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/56982: mutex error (locking against myself) in wdc(4)
 NOIRQcase?
Date: Sun, 28 Aug 2022 21:00:03 +0900

 On 2022/08/28 20:28, Izumi Tsutsui wrote:
 >> wdc(4) with NOIRQ worked on DIGNOSTIC kernel for hpcsh/current a while ago.
 > 
 > Hmm. Maybe I should also check HEAD instead of patched 9.3..
 
 I've checked that -current kernel as of today with DIAGNOSTIC boots
 successfully into multiuser on Jornada 690. (Older) dmesg is:
 
 https://dmesgd.nycbug.org/index.cgi?do=view&id=6287
 
 >> My guess is: This is because wdc(4) for mac68k is too hackish. As tsutsui@
 >> pointed out in port-mac68k/56973, this driver registers interrupt
 >> handler, *AND* it also enables polling mode (ATAC_CAP_NOIRQ).
 >>
 >> I don't know what exactly goes on, but I *imagine* that sometime interrupt
 >> is raised, and sometimes isn't, c.f.:
 > 
 > I don't think it's likely. AFAICT the IDE interrupt has never been
 > triggered at least on my LC630, and Linux/m68k also removed these
 > interrupt register checks:
 >   https://lore.kernel.org/linux-ide/11a56b3317df3bb2ddc15fd29b40b6820e9c7444.1623287706.git.fthain%linux-m68k.org@localhost/
 >   >> This was tested on my Quadra 630. I haven't tested it on my PowerBook 150
 >   >> because I don't have a RAM adapter board for it. It appears that the
 >   >> hardware I tested doesn't need macide_clear_irq() or macide_test_irq().
 >   >> If it did, the generic driver would not have worked. It's possible that
 >   >> those routines are needed for the PowerBook 150 but we can cross that
 >   >> bridge if and when we come to it.
 
 Thanks for explanation. It would be useful to have some comments in
 the source code.
 
 Thanks,
 rin