apple-gmux: Assign apple_gmux_data before registering
Registering the handler after both GPUs will trigger a DDC switch for
connector reprobing. This will oops if apple_gmux_data hasn't already
been assigned. Reorder the code to do that.
[Lukas: More generally, this commit fixes a race condition that
is triggered by invoking a handler callback between the call to
vga_switcheroo_register_handler() and the assignment of
apple_gmux_data.]
Tested-by: Pierre Moreau <pierre.morrow@free.fr>
[MBP 5,3 2009 nvidia MCP79 + G96 pre-retina 15"]
Tested-by: Paul Hordiienko <pvt.gord@gmail.com>
[MBP 6,2 2010 intel ILK + nvidia GT216 pre-retina 15"]
Tested-by: Lukas Wunner <lukas@wunner.de>
[MBP 9,1 2012 intel IVB + nvidia GK107 pre-retina 15"]
Tested-by: William Brown <william@blackhats.net.au>
[MBP 8,2 2011 intel SNB + amd turks pre-retina 15"]
Tested-by: Bruno Bierbaumer <bruno@bierbaumer.net>
[MBP 11,3 2013 intel HSW + nvidia GK107 retina 15"]
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c
index 976efeb..aa58d41 100644
--- a/drivers/platform/x86/apple-gmux.c
+++ b/drivers/platform/x86/apple-gmux.c
@@ -588,18 +588,20 @@
gmux_data->gpe = -1;
}
+ apple_gmux_data = gmux_data;
+ init_completion(&gmux_data->powerchange_done);
+ gmux_enable_interrupts(gmux_data);
+
if (vga_switcheroo_register_handler(&gmux_handler)) {
ret = -ENODEV;
goto err_register_handler;
}
- init_completion(&gmux_data->powerchange_done);
- apple_gmux_data = gmux_data;
- gmux_enable_interrupts(gmux_data);
-
return 0;
err_register_handler:
+ gmux_disable_interrupts(gmux_data);
+ apple_gmux_data = NULL;
if (gmux_data->gpe >= 0)
acpi_disable_gpe(NULL, gmux_data->gpe);
err_enable_gpe: