[Intel-gfx] [PATCH i-g-t] intel_gpu_top: Document how to use JSON output

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Put a note on how to use JSON output into the man page.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
References: https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/issues/100
---
 man/intel_gpu_top.rst | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/man/intel_gpu_top.rst b/man/intel_gpu_top.rst
index f6d74852558b..94fdc6520fd3 100644
--- a/man/intel_gpu_top.rst
+++ b/man/intel_gpu_top.rst
@@ -81,6 +81,11 @@ Filter types: ::
     pci      pci:[vendor=%04x/name][,device=%04x][,card=%d]
              vendor is hex number or vendor name
 
+JSON OUTPUT
+===========
+
+To parse the JSON as output by the tool the consumer should wrap its entirety into square brackets ([ ]). This will make each sample point an JSON array element and will avoid "Multiple root elements" JSON validation error.
+
 LIMITATIONS
 ===========
 
-- 
2.27.0