drm/amd/display: Fix dcn10 cursor set position hang

Calling dcn10_cursor_set_position() before dcn10_cursor_set_attributes()
with invalid (0-value) attributes can cause the ASIC to hang. This fix
checks that address.quadpart is non-zero within set_position before calling
set_attributes.

Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_ipp.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_ipp.c
index 3062b7d..082c98c 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_ipp.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_ipp.c
@@ -614,6 +614,16 @@ static void dcn10_cursor_set_position(
        uint32_t cur_en = pos->enable ? 1 : 0;
        uint32_t dst_x_offset = (src_x_offset >= 0) ? src_x_offset : 0;
 
+       /*
+        * Guard aganst cursor_set_position() from being called with invalid
+        * attributes
+        *
+        * TODO: Look at combining cursor_set_position() and
+        * cursor_set_attributes() into cursor_update()
+        */
+       if (ippn10->curs_attr.address.quad_part == 0)
+               return;
+
        dst_x_offset *= param->ref_clk_khz;
        dst_x_offset /= param->pixel_clk_khz;