re: xsrc/48344: X sesrver crashes with "lockup" on certain i810e-based systems

["John D. Baker" <jdbaker%mylinuxisp.com@localhost>]

The following reply was made to PR xsrc/48344; it has been noted by GNATS.

From: "John D. Baker" <jdbaker%mylinuxisp.com@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: matthew green <mrg%eterna.com.au@localhost>
Subject: re: xsrc/48344: X sesrver crashes with "lockup" on certain i810e-based
 systems
Date: Tue, 22 Jul 2014 13:55:03 -0500 (CDT)

 On Tue, 22 Jul 2014, John D. Baker wrote:
 
 > Now that I have the HP Pavilion something-or-other up and running, I
 > need to make sure this doesn't break things on it.
 
 The HP Pavilion was not affected by the changes.
 
 > Then, I intend to apply a similar change to r1.73 which is the version
 > of the file in the "netbsd-6" branch.
 
 I stepped through each revision of the file until r1.73, applying the
 same changes to arrive at the patch below for the "netbsd-6" and
 related branches.
 
 > There is one quirk:  the mouse pointer is invisble until the first time
 > it needs to be redrawn--crossing an element boundary, button press, etc.
 
 This quirk was apparently present for a while (including on the HP system
 with unmodified netbsd-6) but may be masked depending on what X clients
 run.  For example, if your ".xinitrc" just launches a single XTerm and
 then launches 'twm' with "RandomPlacement", the mouse pointer will be
 invisible until you move into the terminal window or press the left
 button in the root window to bring up the TWM menu.
 
 The following patch lets the X server from "netbsd-6" run on Dell Optiplex
 GX-110 machines.  (Also xf86-video-intel from modular/pkgsrc Xorg unless
 it's been updated to the version that requires KMS.)
 
 +Index: sys/dev/pci/agp_i810.c
 +===================================================================
 +RCS file: /cvsroot/src/sys/dev/pci/agp_i810.c,v
 +retrieving revision 1.73
 +diff -u -p -r1.73 agp_i810.c
 +--- sys/dev/pci/agp_i810.c    4 Apr 2011 20:37:56 -0000       1.73
 ++++ sys/dev/pci/agp_i810.c    22 Jul 2014 15:01:20 -0000
 +@@ -1028,7 +1028,7 @@ agp_i810_bind_memory(struct agp_softc *s
 +              return EINVAL;
 + 
 +      for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
 +-             agp_i810_write_gtt_entry(isc, i, i | 3);
 ++             agp_i810_write_gtt_entry(isc, offset+i, i | 3);
 +      mem->am_is_bound = 1;
 +      return 0;
 + }
 +@@ -1057,7 +1057,7 @@ agp_i810_unbind_memory(struct agp_softc 
 +              return EINVAL;
 + 
 +      for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
 +-             agp_i810_write_gtt_entry(isc, i, 0);
 ++             agp_i810_write_gtt_entry(isc, mem->am_offset+i, 0);
 +      mem->am_is_bound = 0;
 +      return 0;
 + }
 
 NetBSD-current (soon to be NetBSD-7) DRMKMS support on this and similar
 systems is a subject of ongoing investigation.
 
 -- 
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