diff options
Diffstat (limited to 'drivers/platform/x86')
-rw-r--r-- | drivers/platform/x86/apple-gmux.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c index a66be137324c..623d322447a2 100644 --- a/drivers/platform/x86/apple-gmux.c +++ b/drivers/platform/x86/apple-gmux.c @@ -60,6 +60,7 @@ struct apple_gmux_data { /* switcheroo data */ acpi_handle dhandle; int gpe; + bool external_switchable; enum vga_switcheroo_client_id switch_state_display; enum vga_switcheroo_client_id switch_state_ddc; enum vga_switcheroo_client_id switch_state_external; @@ -358,6 +359,19 @@ static const struct backlight_ops gmux_bl_ops = { * ports while the discrete GPU is asleep, but currently we do not make use * of this feature. * + * Our switching policy for the external port is that on those generations + * which are able to switch it fully, the port is switched together with the + * panel when IGD / DIS commands are issued to vga_switcheroo. It is thus + * possible to drive e.g. a beamer on battery power with the integrated GPU. + * The user may manually switch to the discrete GPU if more performance is + * needed. + * + * On all newer generations, the external port can only be driven by the + * discrete GPU. If a display is plugged in while the panel is switched to + * the integrated GPU, *both* GPUs will be in use for maximum performance. + * To decrease power consumption, the user may manually switch to the + * discrete GPU, thereby suspending the integrated GPU. + * * gmux' initial switch state on bootup is user configurable via the EFI * variable ``gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`` (5th byte, * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to @@ -414,7 +428,8 @@ static int gmux_switchto(enum vga_switcheroo_client_id id) { apple_gmux_data->switch_state_ddc = id; apple_gmux_data->switch_state_display = id; - apple_gmux_data->switch_state_external = id; + if (apple_gmux_data->external_switchable) + apple_gmux_data->switch_state_external = id; gmux_write_switch_state(apple_gmux_data); @@ -601,6 +616,11 @@ static struct pci_dev *gmux_get_io_pdev(void) return NULL; } +static int is_thunderbolt(struct device *dev, void *data) +{ + return to_pci_dev(dev)->is_thunderbolt; +} + static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) { struct apple_gmux_data *gmux_data; @@ -755,6 +775,15 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) gmux_data->gpe = -1; } + /* + * If Thunderbolt is present, the external DP port is not fully + * switchable. Force its AUX channel to the discrete GPU. + */ + gmux_data->external_switchable = + !bus_for_each_dev(&pci_bus_type, NULL, NULL, is_thunderbolt); + if (!gmux_data->external_switchable) + gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3); + apple_gmux_data = gmux_data; init_completion(&gmux_data->powerchange_done); gmux_enable_interrupts(gmux_data); |