Changeset 5b0fa60

Timestamp:

05/23/2015 02:14:24 AM (9 years ago)

Author:

Ken Moffat <ken@…>

Branches:

10.0, 10.1, 11.0, 11.1, 11.2, 11.3, 12.0, 12.1, 7.10, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 9.0, 9.1, basic, bdubbs/svn, elogind, kea, ken/TL2024, ken/inkscape-core-mods, ken/tuningfonts, lazarus, lxqt, nosym, perl-modules, plabs/newcss, plabs/python-mods, python3.11, qt5new, rahul/power-profiles-daemon, renodr/vulkan-addition, trunk, upgradedb, xry111/intltool, xry111/llvm18, xry111/soup3, xry111/test-20220226, xry111/xf86-video-removal

Children:

f0e219c

Parents:

ac3058f

Message:

Work around segfault in the Xorg intel driver with gcc-5 and a 4.0 kernel by reinstating UXA and adding a conf file to force that to be used. Tagged as gcc5-checked because it now works in this form, but with misgivings because it clearly does nt work _correctly_. This is a first-stage fix for #6526, but not a final fix.

git-svn-id: svn://svn.linuxfromscratch.org/BLFS/trunk/BOOK@16014 af4574ff-66df-0310-9fd7-8a98e5e911e0

Files:

• introduction/welcome/changelog.xml (modified) (1 diff)
• x/installing/x7driver-intel.xml (modified) (5 diffs)

introduction/welcome/changelog.xml

@@ -48 +48 @@
       <para>May 22st, 2015</para>
       <itemizedlist>
+        <listitem>
+          <para>[ken] - Use UXA acceleration for the intel Xorg driver as
+          a temporary measure, until the gcc-5 and kernel-4.0 problem is
+          better understood.  This is a workaround for
+          <ulink url="&blfs-ticket-root;6526">#6526</ulink>.</para>
+        </listitem>
         <listitem>
           <para>[fernando] - GnuPG 2.1.3 and 4: openpgp tests might fail. Fixes

x/installing/x7driver-intel.xml

@@ -11 +11 @@
   <!ENTITY xorg-intel-driver-md5sum        "fa196a66e52c0c624fe5d350af7a5e7b">
   <!ENTITY xorg-intel-driver-size          "2.2 MB">
-  <!ENTITY xorg-intel-driver-buildsize     "70 MB">
+<!-- commented, remeasured for re-enabling uxa as well as sna
+  <!ENTITY xorg-intel-driver-buildsize     "70 MB"> -->
+  <!ENTITY xorg-intel-driver-buildsize     "78 MB">
   <!ENTITY xorg-intel-driver-time          "0.6 SBU">
 ]>
@@ -33 +35 @@
       </para>
 
-      &lfs77_checked; &gcc5_built;
+      &lfs77_checked; &gcc5_checked;
 
       <note><para>This is a development version of the Intel driver 
@@ -117 +119 @@
       </para>
 
-<screen><userinput>./configure $XORG_CONFIG --enable-kms-only &amp;&amp;
+<screen><userinput>./configure $XORG_CONFIG --enable-kms-only --enable-uxa &amp;&amp;
 make</userinput></screen>
 
@@ -129 +131 @@
 
 <screen role="root"><userinput>make install</userinput></screen>
+
+    </sect3>
+
+    <sect3>
+      <title>Working around problems with the Intel driver</title>
+
+      <para>
+        The SandyBridge New Acceleration (SNA) code is intended to replace the
+        old UXA (UMA Acceleration Architecture), but it is a large body of code
+        and sometimes causes problems. In particular, when a system is built
+        with gcc-5 and kernel headers from linux-4.0, trying to run this driver
+        using SNA will cause a segfault on some, or perhaps all, of the
+        supported chips iff a 4.0 or newer kernel is used (a 3.19.0 kernel, also
+        built with gcc-5, worked ok). To work around this, as well as enabling
+        support for UXA it is necessary to force it to be used by creating a
+        configuration file.
+       </para>
+
+      <para>
+        If this problem applies to you, create the following file as
+        the <systemitem class="username">root</systemitem> user:
+      </para>
+
+<screen role="root"><userinput>cat &gt;&gt; /etc/X11/xorg.conf.d/20-intel.conf &lt;&lt; "EOF"
+<literal>Section "Device"
+        Identifier "Intel Graphics"
+        Driver "intel"
+        Option "AccelMethod" "uxa"
+EndSection</literal>
+EOF</userinput></screen>
 
     </sect3>
@@ -138 +170 @@
         <parameter>--enable-kms-only</parameter>: This switch omits the UMS
         (User Mode Setting) code.
+      </para>
+
+      <para>
+        <parameter>--enable-uxa</parameter>: This switch allows the old UXA code
+        to be compiled in addition to the default SNA.
       </para>