[PATCH 11/11] apple_gmux: Wait for switch completion

[Matthew Garrett]

The GMUX doesn't appear to switch instantly, which can trigger problems in
panel detection and setup. Wait for an interrupt or 200msec, whichever comes
first.

Signed-off-by: Matthew Garrett <matthew.garrett at nebula.com>
---
 drivers/platform/x86/apple-gmux.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/platform/x86/apple-gmux.c 
b/drivers/platform/x86/apple-gmux.c
index 17f906d..6826ede 100644
--- a/drivers/platform/x86/apple-gmux.c
+++ b/drivers/platform/x86/apple-gmux.c
@@ -38,6 +38,7 @@ struct apple_gmux_data {
        int gpe;
        enum vga_switcheroo_client_id resume_client_id;
        enum vga_switcheroo_state power_state;
+       struct completion switch_done;
        struct completion powerchange_done;
 };

@@ -283,6 +284,8 @@ static int gmux_switch_ddc(enum vga_switcheroo_client_id id)

 static int gmux_switchto(enum vga_switcheroo_client_id id)
 {
+       reinit_completion(&apple_gmux_data->switch_done);
+
        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);
@@ -293,6 +296,11 @@ static int gmux_switchto(enum vga_switcheroo_client_id id)
                gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
        }

+       if (apple_gmux_data->gpe >= 0 &&
+           
!wait_for_completion_interruptible_timeout(&apple_gmux_data->switch_done,
+                                                      msecs_to_jiffies(200)))
+               pr_warn("Timeout waiting for gmux GPU switch to complete\n");
+
        return 0;
 }

@@ -401,6 +409,9 @@ static void gmux_notify_handler(acpi_handle device, u32 
value, void *context)
        gmux_clear_interrupts(gmux_data);
        gmux_enable_interrupts(gmux_data);

+       if (status & GMUX_INTERRUPT_STATUS_DISPLAY)
+               complete(&gmux_data->switch_done);
+
        if (status & GMUX_INTERRUPT_STATUS_POWER)
                complete(&gmux_data->powerchange_done);
 }
@@ -565,6 +576,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct 
pnp_device_id *id)
        }

        apple_gmux_data = gmux_data;
+       init_completion(&gmux_data->switch_done);
        init_completion(&gmux_data->powerchange_done);
        gmux_enable_interrupts(gmux_data);

-- 
1.8.5.3