[PATCH] drm/radeon: add bapm module parameter

[Alex Deucher <alexdeucher@gmail.com>]

Add a module paramter to enable bapm on APUs.  It's disabled
by default on certain APUs due to stability issues.  This
option makes it easier to test and to enable it on systems that
are stable.

bug:
https://bugzilla.kernel.org/show_bug.cgi?id=81021

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/radeon/kv_dpm.c      |  5 ++++-
 drivers/gpu/drm/radeon/radeon.h      |  1 +
 drivers/gpu/drm/radeon/radeon_drv.c  |  4 ++++
 drivers/gpu/drm/radeon/trinity_dpm.c | 24 +++++++++++++++---------
 4 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/radeon/kv_dpm.c b/drivers/gpu/drm/radeon/kv_dpm.c
index 9ef8c38..c667d83 100644
--- a/drivers/gpu/drm/radeon/kv_dpm.c
+++ b/drivers/gpu/drm/radeon/kv_dpm.c
@@ -2726,7 +2726,10 @@ int kv_dpm_init(struct radeon_device *rdev)
 	pi->caps_sclk_ds = true;
 	pi->enable_auto_thermal_throttling = true;
 	pi->disable_nb_ps3_in_battery = false;
-	pi->bapm_enable = true;
+	if (radeon_bapm == 0)
+		pi->bapm_enable = false;
+	else
+		pi->bapm_enable = true;
 	pi->voltage_drop_t = 0;
 	pi->caps_sclk_throttle_low_notification = false;
 	pi->caps_fps = false; /* true? */
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 511191f..ef8b23d 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -106,6 +106,7 @@ extern int radeon_vm_size;
 extern int radeon_vm_block_size;
 extern int radeon_deep_color;
 extern int radeon_use_pflipirq;
+extern int radeon_bapm;
 
 /*
  * Copy from radeon_drv.h so we don't have to include both and have conflicting
diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index 5b18af9..a410f41 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -182,6 +182,7 @@ int radeon_vm_size = 8;
 int radeon_vm_block_size = -1;
 int radeon_deep_color = 0;
 int radeon_use_pflipirq = 2;
+int radeon_bapm = -1;
 
 MODULE_PARM_DESC(no_wb, "Disable AGP writeback for scratch registers");
 module_param_named(no_wb, radeon_no_wb, int, 0444);
@@ -261,6 +262,9 @@ module_param_named(deep_color, radeon_deep_color, int, 0444);
 MODULE_PARM_DESC(use_pflipirq, "Pflip irqs for pageflip completion (0 = disable, 1 = as fallback, 2 = exclusive (default))");
 module_param_named(use_pflipirq, radeon_use_pflipirq, int, 0444);
 
+MODULE_PARM_DESC(bapm, "BAPM support (1 = enable, 0 = disable, -1 = auto)");
+module_param_named(bapm, radeon_bapm, int, 0444);
+
 static struct pci_device_id pciidlist[] = {
 	radeon_PCI_IDS
 };
diff --git a/drivers/gpu/drm/radeon/trinity_dpm.c b/drivers/gpu/drm/radeon/trinity_dpm.c
index 32e50be..57f7800 100644
--- a/drivers/gpu/drm/radeon/trinity_dpm.c
+++ b/drivers/gpu/drm/radeon/trinity_dpm.c
@@ -1874,16 +1874,22 @@ int trinity_dpm_init(struct radeon_device *rdev)
 	for (i = 0; i < SUMO_MAX_HARDWARE_POWERLEVELS; i++)
 		pi->at[i] = TRINITY_AT_DFLT;
 
-	/* There are stability issues reported on with
-	 * bapm enabled when switching between AC and battery
-	 * power.  At the same time, some MSI boards hang
-	 * if it's not enabled and dpm is enabled.  Just enable
-	 * it for MSI boards right now.
-	 */
-	if (rdev->pdev->subsystem_vendor == 0x1462)
-		pi->enable_bapm = true;
-	else
+	if (radeon_bapm == -1) {
+		/* There are stability issues reported on with
+		 * bapm enabled when switching between AC and battery
+		 * power.  At the same time, some MSI boards hang
+		 * if it's not enabled and dpm is enabled.  Just enable
+		 * it for MSI boards right now.
+		 */
+		if (rdev->pdev->subsystem_vendor == 0x1462)
+			pi->enable_bapm = true;
+		else
+			pi->enable_bapm = false;
+	} else if (radeon_bapm == 0) {
 		pi->enable_bapm = false;
+	} else {
+		pi->enable_bapm = true;
+	}
 	pi->enable_nbps_policy = true;
 	pi->enable_sclk_ds = true;
 	pi->enable_gfx_power_gating = true;
-- 
1.8.3.1