Hello Jose Abreu,
Commit 97f973d65260 ("drm: Use new mode_valid() helpers in connector
probe helper") from May 25, 2017 (linux-next), leads to the following
Smatch static checker warning:
drivers/gpu/drm/drm_probe_helper.c:102 drm_mode_validate_pipeline()
warn: set error code if '*status != 0'
drivers/gpu/drm/drm_probe_helper.c
89 static int
90 drm_mode_validate_pipeline(struct drm_display_mode *mode,
91 struct drm_connector *connector,
92 struct drm_modeset_acquire_ctx *ctx,
93 enum drm_mode_status *status)
94 {
95 struct drm_device *dev = connector->dev;
96 struct drm_encoder *encoder;
97 int ret;
98
99 /* Step 1: Validate against connector */
100 ret = drm_connector_mode_valid(connector, mode, ctx, status);
101 if (ret || *status != MODE_OK)
--> 102 return ret;
The caller expects ret to be set on error, so if only *status is set
to an error this will do something bad.
103
104 /* Step 2: Validate against encoders and crtcs */
105 drm_connector_for_each_possible_encoder(connector, encoder) {
106 struct drm_bridge *bridge;
107 struct drm_crtc *crtc;
108
109 *status = drm_encoder_mode_valid(encoder, mode);
110 if (*status != MODE_OK) {
111 /* No point in continuing for crtc check as
this encoder
112 * will not accept the mode anyway. If all
encoders
113 * reject the mode then, at exit, ret will not
be
114 * MODE_OK. */
115 continue;
116 }
117
118 bridge = drm_bridge_chain_get_first_bridge(encoder);
119 *status = drm_bridge_chain_mode_valid(bridge,
120
&connector->display_info,
121 mode);
122 drm_bridge_put(bridge);
123 if (*status != MODE_OK) {
124 /* There is also no point in continuing for
crtc check
125 * here. */
126 continue;
127 }
128
129 drm_for_each_crtc(crtc, dev) {
130 if (!drm_encoder_crtc_ok(encoder, crtc))
131 continue;
132
133 *status = drm_crtc_mode_valid(crtc, mode);
134 if (*status == MODE_OK) {
135 /* If we get to this point there is at
least
136 * one combination of encoder+crtc that
works
137 * for this mode. Lets return now. */
138 return 0;
139 }
140 }
141 }
142
143 return 0;
144 }
regards,
dan carpenter
