drm/client: Constify modes

The modes used by the client code live on the connectors' mode
lists, which are not owned by the client code, and thus it has
no business modifying the modes. Mark the modes const to make
that fact abundantly clear.

v2: Fix up the kunit test

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250303093847.7698-1-ville.syrjala@linux.intel.com

diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c
index aca442c25209a95e15c102d7cf4410a2b013042d..b114d1b8793b93f77bda76db4b890bbdd3d37978 100644 (file)
--- a/drivers/gpu/drm/drm_client_modeset.c
+++ b/drivers/gpu/drm/drm_client_modeset.c
@@ -117,10 +117,10 @@ drm_client_find_modeset(struct drm_client_dev *client, struct drm_crtc *crtc)
        return NULL;
 }
 
-static struct drm_display_mode *
+static const struct drm_display_mode *
 drm_connector_get_tiled_mode(struct drm_connector *connector)
 {
-       struct drm_display_mode *mode;
+       const struct drm_display_mode *mode;
 
        list_for_each_entry(mode, &connector->modes, head) {
                if (mode->hdisplay == connector->tile_h_size &&
@@ -130,10 +130,10 @@ drm_connector_get_tiled_mode(struct drm_connector *connector)
        return NULL;
 }
 
-static struct drm_display_mode *
+static const struct drm_display_mode *
 drm_connector_fallback_non_tiled_mode(struct drm_connector *connector)
 {
-       struct drm_display_mode *mode;
+       const struct drm_display_mode *mode;
 
        list_for_each_entry(mode, &connector->modes, head) {
                if (mode->hdisplay == connector->tile_h_size &&
@@ -144,10 +144,10 @@ drm_connector_fallback_non_tiled_mode(struct drm_connector *connector)
        return NULL;
 }
 
-static struct drm_display_mode *
+static const struct drm_display_mode *
 drm_connector_preferred_mode(struct drm_connector *connector, int width, int height)
 {
-       struct drm_display_mode *mode;
+       const struct drm_display_mode *mode;
 
        list_for_each_entry(mode, &connector->modes, head) {
                if (mode->hdisplay > width ||
@@ -159,16 +159,18 @@ drm_connector_preferred_mode(struct drm_connector *connector, int width, int hei
        return NULL;
 }
 
-static struct drm_display_mode *drm_connector_first_mode(struct drm_connector *connector)
+static const struct drm_display_mode *
+drm_connector_first_mode(struct drm_connector *connector)
 {
        return list_first_entry_or_null(&connector->modes,
                                        struct drm_display_mode, head);
 }
 
-static struct drm_display_mode *drm_connector_pick_cmdline_mode(struct drm_connector *connector)
+static const struct drm_display_mode *
+drm_connector_pick_cmdline_mode(struct drm_connector *connector)
 {
-       struct drm_cmdline_mode *cmdline_mode;
-       struct drm_display_mode *mode;
+       const struct drm_cmdline_mode *cmdline_mode;
+       const struct drm_display_mode *mode;
        bool prefer_non_interlace;
 
        /*
@@ -266,13 +268,14 @@ static void drm_client_connectors_enabled(struct drm_connector **connectors,
 static bool drm_client_target_cloned(struct drm_device *dev,
                                     struct drm_connector **connectors,
                                     unsigned int connector_count,
-                                    struct drm_display_mode **modes,
+                                    const struct drm_display_mode **modes,
                                     struct drm_client_offset *offsets,
                                     bool *enabled, int width, int height)
 {
        int count, i, j;
        bool can_clone = false;
-       struct drm_display_mode *dmt_mode, *mode;
+       const struct drm_display_mode *mode;
+       struct drm_display_mode *dmt_mode;
 
        /* only contemplate cloning in the single crtc case */
        if (dev->mode_config.num_crtc > 1)
@@ -351,7 +354,7 @@ fail:
 static int drm_client_get_tile_offsets(struct drm_device *dev,
                                       struct drm_connector **connectors,
                                       unsigned int connector_count,
-                                      struct drm_display_mode **modes,
+                                      const struct drm_display_mode **modes,
                                       struct drm_client_offset *offsets,
                                       int idx,
                                       int h_idx, int v_idx)
@@ -386,7 +389,7 @@ static int drm_client_get_tile_offsets(struct drm_device *dev,
 static bool drm_client_target_preferred(struct drm_device *dev,
                                        struct drm_connector **connectors,
                                        unsigned int connector_count,
-                                       struct drm_display_mode **modes,
+                                       const struct drm_display_mode **modes,
                                        struct drm_client_offset *offsets,
                                        bool *enabled, int width, int height)
 {
@@ -505,7 +508,7 @@ static int drm_client_pick_crtcs(struct drm_client_dev *client,
                                 struct drm_connector **connectors,
                                 unsigned int connector_count,
                                 struct drm_crtc **best_crtcs,
-                                struct drm_display_mode **modes,
+                                const struct drm_display_mode **modes,
                                 int n, int width, int height)
 {
        struct drm_device *dev = client->dev;
@@ -580,7 +583,7 @@ static bool drm_client_firmware_config(struct drm_client_dev *client,
                                       struct drm_connector **connectors,
                                       unsigned int connector_count,
                                       struct drm_crtc **crtcs,
-                                      struct drm_display_mode **modes,
+                                      const struct drm_display_mode **modes,
                                       struct drm_client_offset *offsets,
                                       bool *enabled, int width, int height)
 {
@@ -800,7 +803,7 @@ int drm_client_modeset_probe(struct drm_client_dev *client, unsigned int width,
        struct drm_client_offset *offsets;
        unsigned int connector_count = 0;
        /* points to modes protected by mode_config.mutex */
-       struct drm_display_mode **modes;
+       const struct drm_display_mode **modes;
        struct drm_crtc **crtcs;
        int i, ret = 0;
        bool *enabled;
@@ -871,7 +874,7 @@ int drm_client_modeset_probe(struct drm_client_dev *client, unsigned int width,
        drm_client_modeset_release(client);
 
        for (i = 0; i < connector_count; i++) {
-               struct drm_display_mode *mode = modes[i];
+               const struct drm_display_mode *mode = modes[i];
                struct drm_crtc *crtc = crtcs[i];
                struct drm_client_offset *offset = &offsets[i];
 

diff --git a/drivers/gpu/drm/tests/drm_client_modeset_test.c b/drivers/gpu/drm/tests/drm_client_modeset_test.c
index 7516f6cb36e4e3a1ed3a655de6f6a4479a0efade..cd43d2a52a2dc9df9a860d25139ffdccf31dbbfc 100644 (file)
--- a/drivers/gpu/drm/tests/drm_client_modeset_test.c
+++ b/drivers/gpu/drm/tests/drm_client_modeset_test.c
@@ -88,7 +88,8 @@ static void drm_test_pick_cmdline_res_1920_1080_60(struct kunit *test)
        struct drm_device *drm = priv->drm;
        struct drm_connector *connector = &priv->connector;
        struct drm_cmdline_mode *cmdline_mode = &connector->cmdline_mode;
-       struct drm_display_mode *expected_mode, *mode;
+       struct drm_display_mode *expected_mode;
+       const struct drm_display_mode *mode;
        const char *cmdline = "1920x1080@60";
        int ret;