[PATCH] drm/ttm: let ttm_bo_wait timeout be configurable

[Lepton Wu]

When running dEQP against virgl driver, it turns out the default
15 seconds timeout for ttm_bo_wait is not big enough for
GLES31.functional.ssbo.layout.random.nested_structs_arrays_instance_arrays.22
Change it to a configurable value so we can tune it before virgl
performance gets improved.

Signed-off-by: Lepton Wu <ytht.net at gmail.com>
---
 drivers/gpu/drm/Kconfig      | 2 ++
 drivers/gpu/drm/ttm/Kconfig  | 7 +++++++
 drivers/gpu/drm/ttm/ttm_bo.c | 2 +-
 3 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/ttm/Kconfig

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index bd943a71756c..432054012fa1 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -160,6 +160,8 @@ config DRM_TTM
 	  GPU memory types. Will be enabled automatically if a device driver
 	  uses it.
 
+source "drivers/gpu/drm/ttm/Kconfig"
+
 config DRM_GEM_CMA_HELPER
 	bool
 	depends on DRM
diff --git a/drivers/gpu/drm/ttm/Kconfig b/drivers/gpu/drm/ttm/Kconfig
new file mode 100644
index 000000000000..c7953271c59b
--- /dev/null
+++ b/drivers/gpu/drm/ttm/Kconfig
@@ -0,0 +1,7 @@
+config DRM_TTM_BO_WAIT_TIMEOUT
+	int "Default timeout for ttm bo wait (in seconds)"
+	depends on DRM_TTM
+	default 15
+	help
+	  This option controls the default timeout (in seconds) used in
+	  ttm_bo_wait
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 3f56647cdb35..fb6991811ede 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1709,7 +1709,7 @@ EXPORT_SYMBOL(ttm_bo_unmap_virtual);
 int ttm_bo_wait(struct ttm_buffer_object *bo,
 		bool interruptible, bool no_wait)
 {
-	long timeout = 15 * HZ;
+	long timeout = CONFIG_DRM_TTM_BO_WAIT_TIMEOUT * HZ;
 
 	if (no_wait) {
 		if (reservation_object_test_signaled_rcu(bo->resv, true))
-- 
2.23.0.187.g17f5b7556c-goog