Comment 1 Edwin Groothuis 2007-10-03 04:38:57 UTC

Responsible Changed
From-To: freebsd-ports-bugs->freebsd-x11

Over to maintainer (via the GNATS Auto Assign Tool) 

http://www.freebsd.org/cgi/query-pr.cgi?pr=116851 

Adding to audit trail from misfiled PR ports/116915:
 
Date: Thu, 4 Oct 2007 10:16:28 -0600 (MDT)

The same happens with G550:

(--) MGA(0): Chipset: "mgag550"
(**) MGA(0): Depth 24, (--) framebuffer bpp 32
(==) MGA(0): RGB weight 888
(**) MGA(0): Option "HWcursor" "off"
(**) MGA(0): Option "AGPMode" "4"
(**) MGA(0): Using AGP 4x mode
(==) MGA(0): Using XAA acceleration
(--) MGA(0): Linear framebuffer at 0xFA000000
(**) MGA(0): MMIO registers at 0xF9000000
(--) MGA(0): Pseudo-DMA transfer window at 0xF8800000
(--) MGA(0): BIOS at 0xF9FE0000
Requesting insufficient memory window!: start: 0xf8800000 end: 
0xf9efffff size 0x2000000
(EE) Cannot find empty range to map base to
(WW) MGA(0): Video BIOS info block not detected       !

and the second head is working only in clone mode.

A Solution: Reading The Matrox BIOS As A File



The Problem

The FreeBSD xorg drivers try to map the Matrox video BIOS into a PCI 
range, but fail.  Something (OS? motherboard BIOS?) has mapped something 
else into the available ranges, leaving none big enough to hold the 
0x2000000 size wanted.  xf86GetRange (in xf86Bus.c) finds conflicts [tmp 
= ChkConflict(&r,Acc,SETUP);] and the user sees this message in the Xorg 
log:

Requesting insufficient memory window!: start: 0xdee00000 end: 0xdfefffff size 0
x2000000
(EE) Cannot find empty range to map base to

Without the BIOS, the mga driver has limited function.  This is 
particularly important with the xorg 1.3 xrandr support for multihead 
video boards (MGA450/550).  Newer versions of the mga driver use the 
BIOS to determine how many video connectors the card has; without the 
BIOS, only one is found.



The Solution

Well, maybe not *the* solution, but a solution.  The Linux folks fixed a
similar problem back in April of 2006:

     https://bugs.freedesktop.org/show_bug.cgi?id=6751

That code appears to have been integrated into xorg-server (linuxPci.c, 
Pci.h, and Pci.c).

This is a not-so-quick hack for FreeBSD based on that patch.  It seemed 
like a quick port of the Linux code would work.  But it did not, due to 
a) my inexperience with C; b) the complexity of X and multi-OS support 
(lots of twisty little ARCH_INIT_OS_PCI ifdefs, all alike); c) my 
inability to get pciconf to do what I wanted, and D) possibly badgers.

So I'm documenting a hack that does work in the hopes that it will help 
someone else implement it correctly.


1. Copy the video BIOS from your card to a file.

Real FreeBSD xorg code should read the BIOS data directly from the card. 
Maybe pciconf can do that, but I couldn't figure out how, so I read it 
from a file.  Use Linux to copy the BIOS to a file:

     $ lspci | grep Matrox

     (on my system this is 01:00.0)

     $ cd /sys/bus/pci/devices/0000:01:00.0
     $ echo 1 > rom
     $ cat rom > /tmp/videobios.bin
     $ echo 0 > rom

Save the videobios.bin file somewhere (/tmp/mga/videobios.bin is where 
the patch expects it) and reboot in FreeBSD.


2. Patch xorg-server's Pci.c:

     # cd /usr/ports/x11-servers/xorg-server
     # copy patch-Pci.c (included at the end of this file) to files/
     # make install

Of course this is wrong, the code should be in freebsdPci.c.  However, 
adding the changes in the Linux diff was not enough, and the #ifdefs in 
Pci.h defeated my attempts.  Somebody who knows what they are doing here 
would probably have no trouble.


3.  The Result

Using the experimental mga-1.9.99, xorg log output shows:

(II) Attempted to read BIOS 128KB from /tmp/mga/videobios.bin: got 34KB
(--) MGA(0): Video BIOS info block at offset 0x07D00

Output from xrandr 1.2:

Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 2304 x 1024
VGA1 connected 1280x1024+0+0 375mm x 301mm
    1280x1024      60.0*+   59.9
    1024x768       70.1     60.0
    832x624        74.6
    800x600        72.2     75.0     60.3     56.2
    640x480        75.0     72.8     66.7     60.0
    720x400        70.1 
VGA2 connected 1024x768+0+0 307mm x 230mm
    1024x768       60.0*+   75.1     70.1     60.0*
    832x624        74.6
    800x600        72.2     75.0     60.3     56.2
    640x480        75.0     72.8     66.7     60.0
    720x400        70.1


The Patch

--- hw/xfree86/os-support/bus/Pci.c.orig	2007-09-05 18:48:26.000000000 -0600
+++ hw/xfree86/os-support/bus/Pci.c	2007-10-05 10:40:01.000000000 -0600
@@ -210,6 +210,12 @@
  #include "xf86_OSproc.h"
  #include "Pci.h"

+/* WB: start */
+#include "compiler.h"
+#include <stdio.h>
+#include "xf86_OSlib.h"
+/* WB: end */
+
  #define PCI_MFDEV_SUPPORT   1 /* Include PCI multifunction device support */
  #define PCI_BRIDGE_SUPPORT  1 /* Include support for PCI-to-PCI bridges */

@@ -238,6 +244,9 @@
  			unsigned char * buf, int len, PciBiosType BiosType );

  static int (*pciOSHandleBIOS)(PCITAG Tag, int basereg, unsigned char *buf, int len);
+/* WB: start */
+static int freebsdpciOsHandleBIOS(PCITAG Tag, int basereg, unsigned char *buf, int len);
+/* WB: end */

  int xf86MaxPciDevs = 0;

@@ -1324,6 +1333,13 @@
    PCITAG *pTag;
    int i;

+  /* WB: start */
+  /* this should be in pciOSHandleBIOS */
+  n = freebsdpciOsHandleBIOS(Tag, basereg, buf, len);
+  if (n)
+      return n;
+  /* WB: end */
+
    /* fall back to the old code if the OS code fails */
    if (pciOSHandleBIOS) {
    	n = pciOSHandleBIOS(Tag, basereg, buf, len);
@@ -1415,3 +1431,37 @@
  }

  #endif /* INCLUDE_XF86_NO_DOMAIN */
+
+/* WB: start */
+/* MGA BIOS read code for example only, do not use for real.  Don't even look directly at it. */
+#define BIOSFILE "/tmp/mga/videobios.bin"
+
+int freebsdpciOsHandleBIOS(PCITAG Tag, int basereg, unsigned char *buf, int len)
+{
+    unsigned int fd;
+    struct stat st;
+    int ret;
+    int sofar = 0;
+
+    if (stat(BIOSFILE, &st) == 0)
+    {
+        if ((fd = open(BIOSFILE, O_RDWR)))
+            basereg = 0x0;
+
+        lseek(fd, 0, SEEK_SET);
+        do {
+            /* copy the ROM until we hit Len, EOF or read error */
+            ret = read(fd, buf+sofar, len-sofar);
+            if (ret <= 0)
+                break;
+            sofar += ret;
+        } while (sofar < len);
+
+        close(fd);
+        if (sofar < len)
+            xf86MsgVerb(X_INFO, 3, "Attempted to read BIOS %dKB from %s: got %dKB\n", len/1024, BIOSFILE, sofar/1024);
+        return sofar;
+    }
+    return 0;
+}
+/* WB: end */

-Warren Block * Rapid City, South Dakota USA

When the FreeBSD port of xorg-server starts using libpciaccess, the 
problem reading the video BIOS ROM should be fixed.  Until then, I have 
an easier patch and instructions for xorg-server 1.4.1:

http://www.wonkity.com/~wblock/mgapatch/xorg-patch.txt

-Warren Block * Rapid City, South Dakota USA

Comment 5 Florent Thoumie 2008-01-02 13:34:54 UTC

State Changed
From-To: open->closed

I'm closing this PR cause there's no easy way to fix this in the ports 
collection right now. Please work with xorg maintainers to get your 
patches in the git repo. If it's committed to master but too late for 
1.4.1, I'll reconsider adding it as a local patch. 

In the meantime, I've rolled back the mga driver to 1.4.7 as it seems to 
fix all single-head issues. 

Thanks for your submission.