[PATCH v10 09/13] drm/bridge: cdns-dsi: Move DSI mode check to _atomic_check()

Aradhya Bhatia
2025-02-26T15:57:55Z

At present, the DSI mode configuration check happens during the
_atomic_enable() phase, which is not really the best place for this.
Moreover, if the mode is not valid, the driver gives a warning and
continues the hardware configuration.

Move the DSI mode configuration check to _atomic_check() instead, which
can properly report back any invalid mode, before the _enable phase even
begins.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com>
Signed-off-by: Aradhya Bhatia <aradhya.bhatia@linux.dev>
---
.../gpu/drm/bridge/cadence/cdns-dsi-core.c | 93 ++++++++++++++++++-
1 file changed, 88 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
index 9f0bd07ecefd..93a238205169 100644
--- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
+++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
@@ -425,6 +425,17 @@
#define DSI_NULL_FRAME_OVERHEAD 6
#define DSI_EOT_PKT_SIZE 4

+struct cdns_dsi_bridge_state {
+ struct drm_bridge_state base;
+ struct cdns_dsi_cfg dsi_cfg;
+};
+
+static inline struct cdns_dsi_bridge_state *
+to_cdns_dsi_bridge_state(struct drm_bridge_state *bridge_state)
+{
+ return container_of(bridge_state, struct cdns_dsi_bridge_state, base);
+}
+
static inline struct cdns_dsi *input_to_dsi(struct cdns_dsi_input *input)
{
return container_of(input, struct cdns_dsi, input);
@@ -768,6 +779,8 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
struct cdns_dsi *dsi = input_to_dsi(input);
struct cdns_dsi_output *output = &dsi->output;
+ struct cdns_dsi_bridge_state *dsi_state;
+ struct drm_bridge_state *new_bridge_state;
struct drm_display_mode *mode;
struct phy_configure_opts_mipi_dphy *phy_cfg = &output->phy_opts.mipi_dphy;
unsigned long tx_byte_period;
@@ -778,14 +791,19 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
if (WARN_ON(pm_runtime_get_sync(dsi->base.dev) < 0))
return;

+ new_bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
+ if (WARN_ON(!new_bridge_state))
+ return;
+
+ dsi_state = to_cdns_dsi_bridge_state(new_bridge_state);
+ dsi_cfg = dsi_state->dsi_cfg;
+
if (dsi->platform_ops && dsi->platform_ops->enable)
dsi->platform_ops->enable(dsi);

mode = &bridge->encoder->crtc->state->adjusted_mode;
nlanes = output->dev->lanes;

- WARN_ON_ONCE(cdns_dsi_check_conf(dsi, mode, &dsi_cfg, false));
-
cdns_dsi_hs_init(dsi);
cdns_dsi_init_link(dsi);

@@ -956,6 +974,70 @@ static u32 *cdns_dsi_bridge_get_input_bus_fmts(struct drm_bridge *bridge,
return input_fmts;
}

+static int cdns_dsi_bridge_atomic_check(struct drm_bridge *bridge,
+ struct drm_bridge_state *bridge_state,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state)
+{
+ struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
+ struct cdns_dsi *dsi = input_to_dsi(input);
+ struct cdns_dsi_bridge_state *dsi_state = to_cdns_dsi_bridge_state(bridge_state);
+ const struct drm_display_mode *mode = &crtc_state->mode;
+ struct cdns_dsi_cfg *dsi_cfg = &dsi_state->dsi_cfg;
+
+ return cdns_dsi_check_conf(dsi, mode, dsi_cfg, false);
+}
+
+static struct drm_bridge_state *
+cdns_dsi_bridge_atomic_duplicate_state(struct drm_bridge *bridge)
+{
+ struct cdns_dsi_bridge_state *dsi_state, *old_dsi_state;
+ struct drm_bridge_state *bridge_state;
+
+ if (WARN_ON(!bridge->base.state))
+ return NULL;
+
+ bridge_state = drm_priv_to_bridge_state(bridge->base.state);
+ old_dsi_state = to_cdns_dsi_bridge_state(bridge_state);
+
+ dsi_state = kzalloc(sizeof(*dsi_state), GFP_KERNEL);
+ if (!dsi_state)
+ return NULL;
+
+ __drm_atomic_helper_bridge_duplicate_state(bridge, &dsi_state->base);
+
+ memcpy(&dsi_state->dsi_cfg, &old_dsi_state->dsi_cfg,
+ sizeof(dsi_state->dsi_cfg));
+
+ return &dsi_state->base;
+}
+
+static void
+cdns_dsi_bridge_atomic_destroy_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *state)
+{
+ struct cdns_dsi_bridge_state *dsi_state;
+
+ dsi_state = to_cdns_dsi_bridge_state(state);
+
+ kfree(dsi_state);
+}
+
+static struct drm_bridge_state *
+cdns_dsi_bridge_atomic_reset(struct drm_bridge *bridge)
+{
+ struct cdns_dsi_bridge_state *dsi_state;
+
+ dsi_state = kzalloc(sizeof(*dsi_state), GFP_KERNEL);
+ if (!dsi_state)
+ return NULL;
+
+ memset(dsi_state, 0, sizeof(*dsi_state));
+ dsi_state->base.bridge = bridge;
+
+ return &dsi_state->base;
+}
+
static const struct drm_bridge_funcs cdns_dsi_bridge_funcs = {
.attach = cdns_dsi_bridge_attach,
.mode_valid = cdns_dsi_bridge_mode_valid,
@@ -963,9 +1045,10 @@ static const struct drm_bridge_funcs cdns_dsi_bridge_funcs = {
.atomic_pre_enable = cdns_dsi_bridge_atomic_pre_enable,
.atomic_enable = cdns_dsi_bridge_atomic_enable,
.atomic_post_disable = cdns_dsi_bridge_atomic_post_disable,
- .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
- .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
- .atomic_reset = drm_atomic_helper_bridge_reset,
+ .atomic_check = cdns_dsi_bridge_atomic_check,
+ .atomic_duplicate_state = cdns_dsi_bridge_atomic_duplicate_state,
+ .atomic_destroy_state = cdns_dsi_bridge_atomic_destroy_state,
+ .atomic_reset = cdns_dsi_bridge_atomic_reset,
.atomic_get_input_bus_fmts = cdns_dsi_bridge_get_input_bus_fmts,
};

--
2.34.1