[PATCH xserver v2] autobind GPUs to the screen

Hans de Goede hdegoede at redhat.com
Wed Sep 28 13:42:27 UTC 2016


From: Dave Airlie <airlied at redhat.com>

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 at gmail.com>
[hdegoede at redhat.com: Make configurable, submit upstream]
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
Changes in v2:
-Make the default enabled instead of installing a xorg.conf
 snippet which enables it unconditionally
---
 hw/xfree86/common/xf86Config.c      | 19 +++++++++++++++++++
 hw/xfree86/common/xf86Globals.c     |  2 ++
 hw/xfree86/common/xf86Init.c        | 16 ++++++++++++++++
 hw/xfree86/common/xf86Priv.h        |  1 +
 hw/xfree86/common/xf86Privstr.h     |  1 +
 hw/xfree86/common/xf86platformBus.c |  2 ++
 hw/xfree86/man/Xorg.man             |  7 +++++++
 hw/xfree86/man/xorg.conf.man        |  6 ++++++
 hw/xfree86/modes/xf86Crtc.c         | 28 ++++++++++++++++++++++++++++
 hw/xfree86/modes/xf86Crtc.h         |  3 +++
 10 files changed, 85 insertions(+)

diff --git a/hw/xfree86/common/xf86Config.c b/hw/xfree86/common/xf86Config.c
index 560e2ea..31b34a2 100644
--- a/hw/xfree86/common/xf86Config.c
+++ b/hw/xfree86/common/xf86Config.c
@@ -720,6 +720,7 @@ typedef enum {
     FLAG_DRI2,
     FLAG_USE_SIGIO,
     FLAG_AUTO_ADD_GPU,
+    FLAG_AUTO_BIND_GPU,
     FLAG_MAX_CLIENTS,
     FLAG_IGLX,
 } FlagValues;
@@ -781,6 +782,8 @@ 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,
@@ -860,6 +863,22 @@ 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 07cfabf..072c3fc 100644
--- a/hw/xfree86/common/xf86Globals.c
+++ b/hw/xfree86/common/xf86Globals.c
@@ -136,6 +136,7 @@ xf86InfoRec xf86Info = {
 #else
     .autoAddGPU = FALSE,
 #endif
+    .autoBindGPU = TRUE,
 };
 
 const char *xf86ConfigFile = NULL;
@@ -196,6 +197,7 @@ 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 a544b65..70c5b7a 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 "xf86Bus.h"
@@ -298,6 +299,15 @@ xf86PrivsElevated(void)
 }
 
 static void
+xf86AutoConfigOutputDevices(void)
+{
+    int i;
+
+    for (i = 0; i < xf86NumGPUScreens; i++)
+        xf86AutoConfigOutputDevice(xf86GPUScreens[i], xf86Screens[0]);
+}
+
+static void
 InstallSignalHandlers(void)
 {
     /*
@@ -871,6 +881,8 @@ 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();
@@ -1389,6 +1401,10 @@ 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 c1f8a18..9a3d0df 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 9e327b9..a0a98aa 100644
--- a/hw/xfree86/common/xf86Privstr.h
+++ b/hw/xfree86/common/xf86Privstr.h
@@ -104,6 +104,7 @@ typedef struct {
     MessageType dri2From;
 
     Bool autoAddGPU;
+    Bool autoBindGPU;
 } xf86InfoRec, *xf86InfoPtr;
 
 #ifdef DPMSExtension
diff --git a/hw/xfree86/common/xf86platformBus.c b/hw/xfree86/common/xf86platformBus.c
index 39fb1dd..3e2264f 100644
--- a/hw/xfree86/common/xf86platformBus.c
+++ b/hw/xfree86/common/xf86platformBus.c
@@ -48,6 +48,7 @@
 #include "Pci.h"
 #include "xf86platformBus.h"
 #include "xf86Config.h"
+#include "xf86Crtc.h"
 
 #include "randrstr.h"
 int platformSlotClaimed;
@@ -560,6 +561,7 @@ xf86platformAddDevice(int index)
    }
    /* attach unbound to 0 protocol screen */
    AttachUnboundGPU(xf86Screens[0]->pScreen, xf86GPUScreens[i]->pScreen);
+   xf86AutoConfigOutputDevice(xf86GPUScreens[i], 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 def9bfc..8df6b7d 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 94b199e..bdc121a 100644
--- a/hw/xfree86/man/xorg.conf.man
+++ b/hw/xfree86/man/xorg.conf.man
@@ -676,6 +676,12 @@ 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/hw/xfree86/modes/xf86Crtc.c b/hw/xfree86/modes/xf86Crtc.c
index 966a168..4960678 100644
--- a/hw/xfree86/modes/xf86Crtc.c
+++ b/hw/xfree86/modes/xf86Crtc.c
@@ -3462,3 +3462,31 @@ xf86DetachAllCrtc(ScrnInfoPtr scrn)
             crtc->x = crtc->y = 0;
         }
 }
+
+void xf86AutoConfigOutputDevice(ScrnInfoPtr pScrn, ScrnInfoPtr master)
+{
+    RRProviderPtr master_provider;
+    xf86CrtcConfigPtr config = XF86_CRTC_CONFIG_PTR(master);
+    xf86CrtcConfigPtr slave_config = XF86_CRTC_CONFIG_PTR(pScrn);
+
+    if (!xf86Info.autoBindGPU)
+        return;
+
+    if (!config || !slave_config)
+        return;
+
+    master_provider = config->randr_provider;
+
+    if ((master->capabilities & RR_Capability_SinkOffload) &&
+               pScrn->capabilities & RR_Capability_SourceOffload) {
+        /* source offload */
+        AttachOffloadGPU(master->pScreen, pScrn->pScreen);
+        slave_config->randr_provider->offload_sink = master_provider;
+    }
+    if ((master->capabilities & RR_Capability_SourceOutput) &&
+               pScrn->capabilities & RR_Capability_SinkOutput) {
+        /* sink offload */
+        AttachOutputGPU(master->pScreen, pScrn->pScreen);
+        slave_config->randr_provider->output_source = master_provider;
+    }
+}
diff --git a/hw/xfree86/modes/xf86Crtc.h b/hw/xfree86/modes/xf86Crtc.h
index 14ba9d7..6cf7e89 100644
--- a/hw/xfree86/modes/xf86Crtc.h
+++ b/hw/xfree86/modes/xf86Crtc.h
@@ -1051,4 +1051,7 @@ xf86ProviderSetup(ScrnInfoPtr scrn,
 extern _X_EXPORT void
 xf86DetachAllCrtc(ScrnInfoPtr scrn);
 
+extern _X_EXPORT void
+xf86AutoConfigOutputDevice(ScrnInfoPtr pScrn, ScrnInfoPtr master);
+
 #endif                          /* _XF86CRTC_H_ */
-- 
2.9.3



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