gmux has 3 switch registers:
* GMUX_PORT_SWITCH_DISPLAY switches the panel * GMUX_PORT_SWITCH_DDC switches the panel's DDC lines (only on pre-retinas; on retinas this is a no-op) * GMUX_PORT_SWITCH_EXTERNAL switches the external DP port(s) (only on models without Thunderbolt, i.e. introduced before 2011; those with Thunderbolt switch only HPD/AUX, not the main link)
Currently we switch all 3 registers in unison.
gmux does not preserve the switch state during suspend, so we currently read GMUX_PORT_SWITCH_DISPLAY before suspend and restore all 3 registers to this value on resume.
With the upcoming ->switch_ddc callback, GMUX_PORT_SWITCH_DDC may temporarily contain a different value than the other 2 registers. If we happen to suspend at this moment, we'll write an incorrect value to GMUX_PORT_SWITCH_DDC on resume.
Also, on models with Thunderbolt the integrated GPU is unable to drive the external DP port(s), so we want to keep GMUX_PORT_SWITCH_EXTERNAL permanently switched to the discrete GPU on those machines.
Consequently we can no longer assume that GMUX_PORT_SWITCH_DISPLAY represents the correct value for all 3 registers on suspend.
Track the state of all 3 registers: Add gmux_read_switch_state() and gmux_write_switch_state(). Instead of reading the switch state on every suspend, read it once on driver initialization so that we know the current switch state all the time. (This allows us to use some optimizations and shortcuts, e.g. we can skip switching DDC if we know that it's already switched to the requested GPU.) Change the ->switchto callback to use gmux_write_switch_state().
Tested-by: Lukas Wunner lukas@wunner.de [MBP 9,1 2012 intel IVB + nvidia GK107 pre-retina 15"] Signed-off-by: Lukas Wunner lukas@wunner.de --- drivers/platform/x86/apple-gmux.c | 67 +++++++++++++++++++++++++++------------ 1 file changed, 46 insertions(+), 21 deletions(-)
diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c index c401d49..5c6c708 100644 --- a/drivers/platform/x86/apple-gmux.c +++ b/drivers/platform/x86/apple-gmux.c @@ -57,7 +57,9 @@ struct apple_gmux_data { /* switcheroo data */ acpi_handle dhandle; int gpe; - enum vga_switcheroo_client_id resume_client_id; + enum vga_switcheroo_client_id switch_state_display; + enum vga_switcheroo_client_id switch_state_ddc; + enum vga_switcheroo_client_id switch_state_external; enum vga_switcheroo_state power_state; struct completion powerchange_done; }; @@ -368,17 +370,49 @@ static const struct backlight_ops gmux_bl_ops = { * for the selected GPU. */
+static void gmux_read_switch_state(struct apple_gmux_data *gmux_data) +{ + if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DDC) == 1) + gmux_data->switch_state_ddc = VGA_SWITCHEROO_IGD; + else + gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS; + + if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2) + gmux_data->switch_state_display = VGA_SWITCHEROO_IGD; + else + gmux_data->switch_state_display = VGA_SWITCHEROO_DIS; + + if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2) + gmux_data->switch_state_external = VGA_SWITCHEROO_IGD; + else + gmux_data->switch_state_external = VGA_SWITCHEROO_DIS; +} + +static void gmux_write_switch_state(struct apple_gmux_data *gmux_data) +{ + if (gmux_data->switch_state_ddc == VGA_SWITCHEROO_IGD) + gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 1); + else + gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 2); + + if (gmux_data->switch_state_display == VGA_SWITCHEROO_IGD) + gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2); + else + gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3); + + if (gmux_data->switch_state_external == VGA_SWITCHEROO_IGD) + gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2); + else + gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3); +} + static int gmux_switchto(enum vga_switcheroo_client_id id) { - if (id == VGA_SWITCHEROO_IGD) { - gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1); - gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2); - gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2); - } else { - gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2); - gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3); - gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3); - } + apple_gmux_data->switch_state_ddc = id; + apple_gmux_data->switch_state_display = id; + apple_gmux_data->switch_state_external = id; + + gmux_write_switch_state(apple_gmux_data);
return 0; } @@ -440,15 +474,6 @@ static int gmux_get_client_id(struct pci_dev *pdev) return VGA_SWITCHEROO_DIS; }
-static enum vga_switcheroo_client_id -gmux_active_client(struct apple_gmux_data *gmux_data) -{ - if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2) - return VGA_SWITCHEROO_IGD; - - return VGA_SWITCHEROO_DIS; -} - static const struct vga_switcheroo_handler gmux_handler = { .switchto = gmux_switchto, .power_state = gmux_set_power_state, @@ -513,7 +538,6 @@ static int gmux_suspend(struct device *dev) struct pnp_dev *pnp = to_pnp_dev(dev); struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
- gmux_data->resume_client_id = gmux_active_client(gmux_data); gmux_disable_interrupts(gmux_data); return 0; } @@ -524,7 +548,7 @@ static int gmux_resume(struct device *dev) struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
gmux_enable_interrupts(gmux_data); - gmux_switchto(gmux_data->resume_client_id); + gmux_write_switch_state(gmux_data); if (gmux_data->power_state == VGA_SWITCHEROO_OFF) gmux_set_discrete_state(gmux_data, gmux_data->power_state); return 0; @@ -704,6 +728,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) apple_gmux_data = gmux_data; init_completion(&gmux_data->powerchange_done); gmux_enable_interrupts(gmux_data); + gmux_read_switch_state(gmux_data);
if (vga_switcheroo_register_handler(&gmux_handler, 0)) { ret = -ENODEV;