From 471289fa1dc359555ceed6302f7d9605ab6be3ea Mon Sep 17 00:00:00 2001
From: Dave Airlie <airlied@redhat.com>
Date: Mon, 2 Apr 2018 16:49:02 -0400
Subject: [PATCH] autobind GPUs to the screen

This is a modified version of a patch we've been carry-ing in Fedora and
RHEL for years now. This patch automatically adds secondary GPUs to the
master as output sink / offload source making e.g. the use of
slave-outputs just work, with requiring the user to manually run
"xrandr --setprovideroutputsource" before he can hookup an external
monitor to his hybrid graphics laptop.

There is one problem with this patch, which is why it was not upstreamed
before. What to do when a secondary GPU gets detected really is a policy
decission (e.g. one may want to autobind PCI GPUs but not USB ones) and
as such should be under control of the Desktop Environment.

Unconditionally adding autobinding support to the xserver will result
in races between the DE dealing with the hotplug of a secondary GPU
and the server itself dealing with it.

However we've waited for years for any Desktop Environments to actually
start doing some sort of autoconfiguration of secondary GPUs and there
is still not a single DE dealing with this, so I believe that it is
time to upstream this now.

To avoid potential future problems if any DEs get support for doing
secondary GPU configuration themselves, the new autobind functionality
is made optional. Since no DEs currently support doing this themselves it
is enabled by default. When DEs grow support for doing this themselves
they can disable the servers autobinding through the servers cmdline or a
xorg.conf snippet.

Signed-off-by: Dave Airlie <airlied@gmail.com>
[hdegoede@redhat.com: Make configurable, fix with nvidia, submit upstream]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 hw/xfree86/common/xf86Config.c      | 19 +++++++++++++++++++
 hw/xfree86/common/xf86Globals.c     |  2 ++
 hw/xfree86/common/xf86Init.c        | 20 ++++++++++++++++++++
 hw/xfree86/common/xf86Priv.h        |  1 +
 hw/xfree86/common/xf86Privstr.h     |  1 +
 hw/xfree86/common/xf86platformBus.c |  4 ++++
 hw/xfree86/man/Xorg.man             |  7 +++++++
 hw/xfree86/man/xorg.conf.man        |  6 ++++++
 randr/randrstr.h                    |  3 +++
 randr/rrprovider.c                  | 22 ++++++++++++++++++++++
 10 files changed, 85 insertions(+)

diff --git a/hw/xfree86/common/xf86Config.c b/hw/xfree86/common/xf86Config.c
index 2c1d335..d7d7c2e 100644
--- a/hw/xfree86/common/xf86Config.c
+++ b/hw/xfree86/common/xf86Config.c
@@ -643,6 +643,7 @@ typedef enum {
     FLAG_DRI2,
     FLAG_USE_SIGIO,
     FLAG_AUTO_ADD_GPU,
+    FLAG_AUTO_BIND_GPU,
     FLAG_MAX_CLIENTS,
     FLAG_IGLX,
     FLAG_DEBUG,
@@ -699,6 +700,8 @@ static OptionInfoRec FlagOptions[] = {
      {0}, FALSE},
     {FLAG_AUTO_ADD_GPU, "AutoAddGPU", OPTV_BOOLEAN,
      {0}, FALSE},
+    {FLAG_AUTO_BIND_GPU, "AutoBindGPU", OPTV_BOOLEAN,
+     {0}, FALSE},
     {FLAG_MAX_CLIENTS, "MaxClients", OPTV_INTEGER,
      {0}, FALSE },
     {FLAG_IGLX, "IndirectGLX", OPTV_BOOLEAN,
@@ -779,6 +782,22 @@ configServerFlags(XF86ConfFlagsPtr flagsconf, XF86OptionPtr layoutopts)
     }
     xf86Msg(from, "%sutomatically adding GPU devices\n",
             xf86Info.autoAddGPU ? "A" : "Not a");
+
+    if (xf86AutoBindGPUDisabled) {
+        xf86Info.autoBindGPU = FALSE;
+        from = X_CMDLINE;
+    }
+    else if (xf86IsOptionSet(FlagOptions, FLAG_AUTO_BIND_GPU)) {
+        xf86GetOptValBool(FlagOptions, FLAG_AUTO_BIND_GPU,
+                          &xf86Info.autoBindGPU);
+        from = X_CONFIG;
+    }
+    else {
+        from = X_DEFAULT;
+    }
+    xf86Msg(from, "%sutomatically binding GPU devices\n",
+            xf86Info.autoBindGPU ? "A" : "Not a");
+
     /*
      * Set things up based on the config file information.  Some of these
      * settings may be overridden later when the command line options are
diff --git a/hw/xfree86/common/xf86Globals.c b/hw/xfree86/common/xf86Globals.c
index e890f05..7b27b4c 100644
--- a/hw/xfree86/common/xf86Globals.c
+++ b/hw/xfree86/common/xf86Globals.c
@@ -131,6 +131,7 @@ xf86InfoRec xf86Info = {
 #else
     .autoAddGPU = FALSE,
 #endif
+    .autoBindGPU = TRUE,
 };
 
 const char *xf86ConfigFile = NULL;
@@ -191,6 +192,7 @@ Bool xf86FlipPixels = FALSE;
 Gamma xf86Gamma = { 0.0, 0.0, 0.0 };
 
 Bool xf86AllowMouseOpenFail = FALSE;
+Bool xf86AutoBindGPUDisabled = FALSE;
 
 #ifdef XF86VIDMODE
 Bool xf86VidModeDisabled = FALSE;
diff --git a/hw/xfree86/common/xf86Init.c b/hw/xfree86/common/xf86Init.c
index ea42ec9..ec255b6 100644
--- a/hw/xfree86/common/xf86Init.c
+++ b/hw/xfree86/common/xf86Init.c
@@ -76,6 +76,7 @@
 #include "xf86DDC.h"
 #include "xf86Xinput.h"
 #include "xf86InPriv.h"
+#include "xf86Crtc.h"
 #include "picturestr.h"
 #include "randrstr.h"
 #include "glxvndabi.h"
@@ -237,6 +238,19 @@ xf86PrivsElevated(void)
     return PrivsElevated();
 }
 
+static void
+xf86AutoConfigOutputDevices(void)
+{
+    int i;
+
+    if (!xf86Info.autoBindGPU)
+        return;
+
+    for (i = 0; i < xf86NumGPUScreens; i++)
+        RRProviderAutoConfigGpuScreen(xf86ScrnToScreen(xf86GPUScreens[i]),
+                                      xf86ScrnToScreen(xf86Screens[0]));
+}
+
 static void
 TrapSignals(void)
 {
@@ -770,6 +784,8 @@ InitOutput(ScreenInfo * pScreenInfo, int argc, char **argv)
     for (i = 0; i < xf86NumGPUScreens; i++)
         AttachUnboundGPU(xf86Screens[0]->pScreen, xf86GPUScreens[i]->pScreen);
 
+    xf86AutoConfigOutputDevices();
+
     xf86VGAarbiterWrapFunctions();
     if (sigio_blocked)
         input_unlock();
@@ -1278,6 +1294,10 @@ ddxProcessArgument(int argc, char **argv, int i)
         xf86Info.iglxFrom = X_CMDLINE;
         return 0;
     }
+    if (!strcmp(argv[i], "-noautoBindGPU")) {
+        xf86AutoBindGPUDisabled = TRUE;
+        return 1;
+    }
 
     /* OS-specific processing */
     return xf86ProcessArgument(argc, argv, i);
diff --git a/hw/xfree86/common/xf86Priv.h b/hw/xfree86/common/xf86Priv.h
index 4fe2b5f..6566622 100644
--- a/hw/xfree86/common/xf86Priv.h
+++ b/hw/xfree86/common/xf86Priv.h
@@ -46,6 +46,7 @@
 extern _X_EXPORT const char *xf86ConfigFile;
 extern _X_EXPORT const char *xf86ConfigDir;
 extern _X_EXPORT Bool xf86AllowMouseOpenFail;
+extern _X_EXPORT Bool xf86AutoBindGPUDisabled;
 
 #ifdef XF86VIDMODE
 extern _X_EXPORT Bool xf86VidModeDisabled;
diff --git a/hw/xfree86/common/xf86Privstr.h b/hw/xfree86/common/xf86Privstr.h
index 21c2e1f..6c71863 100644
--- a/hw/xfree86/common/xf86Privstr.h
+++ b/hw/xfree86/common/xf86Privstr.h
@@ -98,6 +98,7 @@ typedef struct {
 
     Bool autoAddGPU;
     const char *debug;
+    Bool autoBindGPU;
 } xf86InfoRec, *xf86InfoPtr;
 
 /* ISC's cc can't handle ~ of UL constants, so explicitly type cast them. */
diff --git a/hw/xfree86/common/xf86platformBus.c b/hw/xfree86/common/xf86platformBus.c
index cef47da..913a324 100644
--- a/hw/xfree86/common/xf86platformBus.c
+++ b/hw/xfree86/common/xf86platformBus.c
@@ -49,6 +49,7 @@
 #include "Pci.h"
 #include "xf86platformBus.h"
 #include "xf86Config.h"
+#include "xf86Crtc.h"
 
 #include "randrstr.h"
 int platformSlotClaimed;
@@ -665,6 +666,9 @@ xf86platformAddDevice(int index)
    }
    /* attach unbound to 0 protocol screen */
    AttachUnboundGPU(xf86Screens[0]->pScreen, xf86GPUScreens[i]->pScreen);
+   if (xf86Info.autoBindGPU)
+       RRProviderAutoConfigGpuScreen(xf86ScrnToScreen(xf86GPUScreens[i]),
+                                     xf86ScrnToScreen(xf86Screens[0]));
 
    RRResourcesChanged(xf86Screens[0]->pScreen);
    RRTellChanged(xf86Screens[0]->pScreen);
diff --git a/hw/xfree86/man/Xorg.man b/hw/xfree86/man/Xorg.man
index 13a9dc3..745f986 100644
--- a/hw/xfree86/man/Xorg.man
+++ b/hw/xfree86/man/Xorg.man
@@ -283,6 +283,13 @@ is a comma separated list of directories to search for
 server modules.  This option is only available when the server is run
 as root (i.e, with real-uid 0).
 .TP 8
+.B \-noautoBindGPU
+Disable automatically setting secondary GPUs up as output sinks and offload
+sources. This is equivalent to setting the
+.B AutoBindGPU
+xorg.conf(__filemansuffix__) file option. To
+.B false.
+.TP 8
 .B \-nosilk
 Disable Silken Mouse support.
 .TP 8
diff --git a/hw/xfree86/man/xorg.conf.man b/hw/xfree86/man/xorg.conf.man
index 9589262..8d51e06 100644
--- a/hw/xfree86/man/xorg.conf.man
+++ b/hw/xfree86/man/xorg.conf.man
@@ -672,6 +672,12 @@ Enabled by default.
 If this option is disabled, then no GPU devices will be added from the udev
 backend. Enabled by default. (May need to be disabled to setup Xinerama).
 .TP 7
+.BI "Option \*qAutoBindGPU\*q  \*q" boolean \*q
+If enabled then secondary GPUs will be automatically set up as output-sinks and
+offload-sources. Making e.g. laptop outputs connected only to the secondary
+GPU directly available for use without needing to run
+"xrandr --setprovideroutputsource". Enabled by default.
+.TP 7
 .BI "Option \*qLog\*q \*q" string \*q
 This option controls whether the log is flushed and/or synced to disk after
 each message.
diff --git a/randr/randrstr.h b/randr/randrstr.h
index f94174b..092d726 100644
--- a/randr/randrstr.h
+++ b/randr/randrstr.h
@@ -1039,6 +1039,9 @@ RRProviderLookup(XID id, RRProviderPtr *provider_p);
 extern _X_EXPORT void
 RRDeliverProviderEvent(ClientPtr client, WindowPtr pWin, RRProviderPtr provider);
 
+extern _X_EXPORT void
+RRProviderAutoConfigGpuScreen(ScreenPtr pScreen, ScreenPtr masterScreen);
+
 /* rrproviderproperty.c */
 
 extern _X_EXPORT void
diff --git a/randr/rrprovider.c b/randr/rrprovider.c
index e4bc2bf..e04c18f 100644
--- a/randr/rrprovider.c
+++ b/randr/rrprovider.c
@@ -485,3 +485,25 @@ RRDeliverProviderEvent(ClientPtr client, WindowPtr pWin, RRProviderPtr provider)
 
     WriteEventsToClient(client, 1, (xEvent *) &pe);
 }
+
+void
+RRProviderAutoConfigGpuScreen(ScreenPtr pScreen, ScreenPtr masterScreen)
+{
+    rrScrPrivPtr pScrPriv = rrGetScrPriv(pScreen);
+    rrScrPrivPtr masterPriv = rrGetScrPriv(masterScreen);
+    RRProviderPtr provider = pScrPriv->provider;
+    RRProviderPtr master_provider = masterPriv->provider;
+
+    if (!provider || !master_provider)
+        return;
+
+    if ((provider->capabilities & RR_Capability_SinkOutput) &&
+        (master_provider->capabilities & RR_Capability_SourceOutput)) {
+        pScrPriv->rrProviderSetOutputSource(pScreen, provider, master_provider);
+        RRInitPrimeSyncProps(pScreen);
+    }
+
+    if ((provider->capabilities & RR_Capability_SourceOffload) &&
+        (master_provider->capabilities & RR_Capability_SinkOffload))
+        pScrPriv->rrProviderSetOffloadSink(pScreen, provider, master_provider);
+}
-- 
2.16.2