GPU Check: fixed to work on non-Tesla cards

Signed-off-by: Nicola Vigano <nicola.vigano@esrf.fr>

5_reconstruction/gtCheckGpu.m

 function gpu_ok = gtCheckGpu()
-    [status, out] = unix('nvidia-smi | grep Tesla');
-    if ~status && length(out) > 10
-       gpu_ok = true;
-    else
-       gpu_ok = false;
+    % First get list of GPUs
+    [ret_code, msg] = unix('nvidia-smi -L');
+    if (ret_code)
+        disp('No nVidia driver installed!')
+        gpu_ok = false;
+        return;
+    end
+    % It could be both UUID and S/N, so ".+?" matches both
+    gpus = regexp(msg, '\(.+?: (?<uuid>.*?)\)', 'names');
+
+    % Now Let's find a GPU which is not attached to a monitor
+    for ii = 1:numel(gpus)
+        [~, msg] = unix(['nvidia-smi -q -i ' gpus(ii).uuid]);
+        displayMode = regexp(msg, 'Display Mode\s*: (?<mode>.*?)\n', 'tokens');
+        if (strcmp(displayMode{1}, 'Disabled'))
+            gpu_ok = true;
+            return;
+        end
+    end
+    gpu_ok = false;
 end