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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-12-31 13:39:42 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-12-31 13:39:42 +0100 |
| commit | f244d8b623dae7a7bc695b0336f67729b95a9736 (patch) | |
| tree | b189aea80aaa312343088f7753e7971e70884e06 /drivers/acpi/bus.c | |
| parent | f26ca1d699e8b54a50d9faf82327d3c2072aaedd (diff) | |
| download | linux-f244d8b623dae7a7bc695b0336f67729b95a9736.tar.gz linux-f244d8b623dae7a7bc695b0336f67729b95a9736.tar.bz2 linux-f244d8b623dae7a7bc695b0336f67729b95a9736.zip | |
ACPIPHP / radeon / nouveau: Fix VGA switcheroo problem related to hotplug
The changes in the ACPI-based PCI hotplug (ACPIPHP) subsystem made
during the 3.12 development cycle uncovered a problem with VGA
switcheroo that on some systems, when the device-specific method
(ATPX in the radeon case, _DSM in the nouveau case) is used to turn
off the discrete graphics, the BIOS generates ACPI hotplug events for
that device and those events cause ACPIPHP to attempt to remove the
device from the system (they are events for a device that was present
previously and is not present any more, so that's what should be done
according to the spec). Then, the system stops functioning correctly.
Since the hotplug events in question were simply silently ignored
previously, the least intrusive way to address that problem is to
make ACPIPHP ignore them again. For this purpose, introduce a new
ACPI device flag, no_hotplug, and modify ACPIPHP to ignore hotplug
events for PCI devices whose ACPI companions have that flag set.
Next, make the radeon and nouveau switcheroo detection code set the
no_hotplug flag for the discrete graphics' ACPI companion.
Fixes: bbd34fcdd1b2 (ACPI / hotplug / PCI: Register all devices under the given bridge)
References: https://bugzilla.kernel.org/show_bug.cgi?id=61891
References: https://bugzilla.kernel.org/show_bug.cgi?id=64891
Reported-and-tested-by: Mike Lothian <mike@fireburn.co.uk>
Reported-and-tested-by: <madcatx@atlas.cz>
Reported-and-tested-by: Joaquín Aramendía <samsagax@gmail.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 3.12+ <stable@vger.kernel.org> # 3.12+
Diffstat (limited to 'drivers/acpi/bus.c')
| -rw-r--r-- | drivers/acpi/bus.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index bba9b72e25f8..0710004055c8 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -156,6 +156,16 @@ int acpi_bus_get_private_data(acpi_handle handle, void **data) } EXPORT_SYMBOL(acpi_bus_get_private_data); +void acpi_bus_no_hotplug(acpi_handle handle) +{ + struct acpi_device *adev = NULL; + + acpi_bus_get_device(handle, &adev); + if (adev) + adev->flags.no_hotplug = true; +} +EXPORT_SYMBOL_GPL(acpi_bus_no_hotplug); + static void acpi_print_osc_error(acpi_handle handle, struct acpi_osc_context *context, char *error) { |