From db183d95a4b03a735da54609b6158e17b0422e62 Mon Sep 17 00:00:00 2001
From: Julien Cristau <jcristau@debian.org>
Date: Tue, 24 Feb 2009 01:25:32 +0100
Subject: [PATCH] Add an fbdev screen as a fallback on sparc

Because of a bug in our PCI code that got exposed by recent kernels,
we will fail to start with PCI drivers on sparc.  Add a new fallback
screen using the fbdev driver that should hopefully still work.

For this to work we need xf86MapDomainMemory to not throw a fatal error
on failure, otherwise we won't even try the fallback.
---
 hw/xfree86/common/xf86Config.c       |   65 ++++++++++++++++++++++++++++++++++
 hw/xfree86/os-support/bus/linuxPci.c |    4 +-
 2 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/hw/xfree86/common/xf86Config.c b/hw/xfree86/common/xf86Config.c
index 3c29497..05776f4 100644
--- a/hw/xfree86/common/xf86Config.c
+++ b/hw/xfree86/common/xf86Config.c
@@ -1531,6 +1531,51 @@ static OptionInfoRec LayoutOptions[] = {
        {0}, FALSE },
 };
 
+#ifdef __sparc__
+/*
+ * XXX this is a kludge to workaround a bug on sparc that makes X fail to
+ * start on pci platforms, and where we want to always fallback to fbdev.
+ */
+static void configAddFbdev(XF86ConfLayoutPtr conf_layout)
+{
+    XF86ConfScreenPtr fbdev_screen = xnfcalloc(1, sizeof(XF86ConfScreenRec));
+    XF86ConfDevicePtr fbdev_device = xnfcalloc(1, sizeof(XF86ConfDeviceRec));
+    XF86ConfAdjacencyPtr fbdev_adjp = xnfcalloc(1, sizeof(XF86ConfAdjacencyRec));
+
+    fbdev_adjp->adj_scrnum = -1;
+    fbdev_adjp->adj_screen = fbdev_screen;
+    fbdev_adjp->adj_screen_str = xstrdup("fbdev fallback Screen");
+    fbdev_adjp->adj_where = CONF_ADJ_OBSOLETE;
+
+    fbdev_screen->scrn_identifier = xstrdup(fbdev_adjp->adj_screen_str);
+    fbdev_screen->scrn_device_str = xstrdup("fbdev fallback Device");
+    fbdev_screen->scrn_device = fbdev_device;
+
+    fbdev_device->dev_identifier = xstrdup(fbdev_screen->scrn_device_str);
+    fbdev_device->dev_driver = xstrdup("fbdev");
+
+    conf_layout->lay_adjacency_lst =
+	xf86addListItem(&conf_layout->lay_adjacency_lst->list,
+                        &fbdev_adjp->list);
+}
+
+static XF86ConfScreenPtr configAddFbdevScreen(void)
+{
+    XF86ConfScreenPtr fbdev_screen = xnfcalloc(1, sizeof(XF86ConfScreenRec));
+    XF86ConfDevicePtr fbdev_device = xnfcalloc(1, sizeof(XF86ConfDeviceRec));
+
+    fbdev_screen->scrn_identifier = xstrdup("fbdev fallback Screen");
+    fbdev_screen->scrn_device_str = xstrdup("fbdev fallback Device");
+    fbdev_screen->scrn_device = fbdev_device;
+
+    fbdev_device->dev_identifier = xstrdup(fbdev_screen->scrn_device_str);
+    fbdev_device->dev_driver = xstrdup("fbdev");
+
+    return fbdev_screen;
+
+}
+#endif
+
 /*
  * figure out which layout is active, which screens are used in that layout,
  * which drivers and monitors are used in these screens
@@ -1577,6 +1622,9 @@ configLayout(serverLayoutPtr servlayoutp, XF86ConfLayoutPtr conf_layout,
     }
     xf86Msg(from, "ServerLayout \"%s\"\n", conf_layout->lay_identifier);
     adjp = conf_layout->lay_adjacency_lst;
+#ifdef __sparc__
+    configAddFbdev(conf_layout);
+#endif
 
     /*
      * we know that each screen is referenced exactly once on the left side
@@ -1826,13 +1874,30 @@ configImpliedLayout(serverLayoutPtr servlayoutp, XF86ConfScreenPtr conf_screen)
 
     /* We have exactly one screen */
 
+#ifndef __sparc__
     slp = xnfcalloc(1, 2 * sizeof(screenLayoutRec));
+#else
+    slp = xnfcalloc(3, sizeof(screenLayoutRec));
+#endif
+
     slp[0].screen = xnfcalloc(1, sizeof(confScreenRec));
+#ifndef __sparc__
     slp[1].screen = NULL;
+#else
+    slp[1].screen = xnfcalloc(1, sizeof(confScreenRec));
+    slp[2].screen = NULL;
+#endif
     if (!configScreen(slp[0].screen, conf_screen, 0, from)) {
 	xfree(slp);
 	return FALSE;
     }
+#ifdef __sparc__
+    conf_screen = configAddFbdevScreen();
+    if (!configScreen(slp[1].screen, conf_screen, 1, X_DEFAULT)) {
+	xfree(slp);
+	return FALSE;
+    }
+#endif
     servlayoutp->id = "(implicit)";
     servlayoutp->screens = slp;
     servlayoutp->inactives = xnfcalloc(1, sizeof(GDevRec));
diff --git a/hw/xfree86/os-support/bus/linuxPci.c b/hw/xfree86/os-support/bus/linuxPci.c
index 9a9a99d..8b04426 100644
--- a/hw/xfree86/os-support/bus/linuxPci.c
+++ b/hw/xfree86/os-support/bus/linuxPci.c
@@ -703,8 +703,8 @@ xf86MapDomainMemory(int ScreenNum, int Flags, PCITAG Tag,
     if (fd >= 0)
 	close(fd);
     if (addr == NULL || addr == MAP_FAILED) {
-	perror("mmap failure");
-	FatalError("xf86MapDomainMem():  mmap() failure\n");
+	ErrorF("xf86MapDomainMem():  %s\n", strerror(errno));
+	addr = NULL;
     }
     return addr;
 }
-- 
1.6.1.3