[PATCH 4/4] drm/radeon/atif: Send a hotplug event when we get dgpu display request

[Alex Deucher]

On PX systems, if the platform supports hotplug events ATIF while the
dGPU is powered down, handle the event and alert userspace.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/radeon/radeon_acpi.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_acpi.c b/drivers/gpu/drm/radeon/radeon_acpi.c
index 31c9a92..6efbd65 100644
--- a/drivers/gpu/drm/radeon/radeon_acpi.c
+++ b/drivers/gpu/drm/radeon/radeon_acpi.c
@@ -25,6 +25,7 @@
 #include <linux/acpi.h>
 #include <linux/slab.h>
 #include <linux/power_supply.h>
+#include <linux/pm_runtime.h>
 #include <acpi/video.h>
 #include <drm/drmP.h>
 #include <drm/drm_crtc_helper.h>
@@ -32,6 +33,12 @@
 #include "radeon_acpi.h"
 #include "atom.h"
 
+#if defined(CONFIG_VGA_SWITCHEROO)
+bool radeon_atpx_dgpu_req_power_for_displays(void);
+#else
+static inline bool radeon_atpx_dgpu_req_power_for_displays(void) { return false; }
+#endif
+
 #define ACPI_AC_CLASS           "ac_adapter"
 
 extern void radeon_pm_acpi_event_handler(struct radeon_device *rdev);
@@ -394,6 +401,16 @@ int radeon_atif_handler(struct radeon_device *rdev,
 #endif
 		}
 	}
+	if (req.pending & ATIF_DGPU_DISPLAY_EVENT) {
+		if ((rdev->flags & RADEON_IS_PX) &&
+		    radeon_atpx_dgpu_req_power_for_displays()) {
+			pm_runtime_get_sync(rdev->ddev->dev);
+			/* Just fire off a uevent and let userspace tell us what to do */
+			drm_helper_hpd_irq_event(rdev->ddev);
+			pm_runtime_mark_last_busy(rdev->ddev->dev);
+			pm_runtime_put_autosuspend(rdev->ddev->dev);
+		}
+	}
 	/* TODO: check other events */
 
 	/* We've handled the event, stop the notifier chain. The ACPI interface
-- 
2.5.5