Re: port-alpha/33073 (isp0: unable to load dma (22))

[Michael Haardt <michael%moria.de@localhost>]

The following reply was made to PR port-alpha/33073; it has been noted by GNATS.

From: Michael Haardt <michael%moria.de@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: port-alpha/33073 (isp0: unable to load dma (22))
Date: Tue, 20 Jul 2021 23:09:57 +0200

 thorpej%NetBSD.org@localhost wrote:
 
 > Synopsis: isp0: unable to load dma (22)
 > 
 > State-Changed-From-To: feedback->closed
 > State-Changed-By: thorpej%NetBSD.org@localhost
 > State-Changed-When: Sun, 18 Jul 2021 19:36:16 +0000
 > State-Changed-Why:
 > This would have been significantly mitigated by:
 > 
 > ----------------------------
 > revision 1.21
 > date: 2007-03-13 18:40:14 -0700;  author: mhitch;  state: Exp;  lines: +9 -3;
 > branches:  1.21.36;  1.21.38;  1.21.40;
 > Contrary to the comment in cia_dma_get_tag(), there are machines with cia
 > that have over 1.0G.  Allow direct dma requests to fall back to SGMAPs.
 > my PWS 500au with 1.5G of memory now works with dma operations.
 > ----------------------------
 
 I have my PWS 500au running again and tried to install NetBSD 9.2 booting
 from NFS.  I could access the disk, label it, make a filesystem and unpack
 some sets, but in the middle of doing so this happened (serial console):
 
      Status: Running
     Command: progress -zf /mnt2//base.tgz tar --chroot -xpf -
 
 --------------------------------------------------------------------------------
 
 [ 164.4571095] isp0: unable to load DMA (35)orrectable error.
 [ 164.5127761] sd0(isp0:0:0:0): adapter resource shortageror.
 [ 165.5752672] isp0: unable to load DMA (35)orrectable error.
 [ 165.6216871] sd0(isp0:0:0:0): adapter resource shortageror.
 [ 161.5229999] Warning: received processor correctable error.
 [ 161.5885140] Warning: received processor correctable error.
 [ 161.6540279] Warning: received processor correctable error.
 [ 161.7195428] Warning: received processor correctable error.
 
 > ...but a more comprehensive fix was made in:
 > 
 > ----------------------------
 > revision 1.35
 > date: 2021-07-16 17:30:39 -0700;  author: thorpej;  state: Exp;  lines: +92 -30;  commitid: hTyTdpdUfhyl2h1D;
 > Back in rev 1.21, mhitch@ fixed an issue with his 1.5GB RAM PWS 500au
 > by using a fall-back to the ISA DMA window if DMA was out of range for
 > the 1G @ 1G PCI DMA window.  Alas, the ISA DMA window is pretty small
 > (8M @ 8M), and it's possible to starve it with PCI devices that might
 > have, for example, large control data structures there.
 > 
 > So, instead, if the system has more than 1G of RAM, use Window 3
 > (previously unused) as a SGMAP window 1G @ 3G, and set that as the
 > fall-back if the direct-mapped window fails.
 > ----------------------------
 > 
 > ...of alpha/pci/cia_dma.c
 
 Should I still try removing 512 MB from the machine to see if it works
 fine with 1 GB? Given the date, I guess this change is not yet in 9.2.
 Is there a newer instkernel to try that includes this change?
 
 Michael