This reverts commit e351e4d5eaec ("drm/bridge: Add the necessary bits
to support bus format negotiation"). Commit 6ed7e9625fa6 ("drm/bridge:
Add a drm_bridge_state object") introduced a circular dependency
between drm.ko and drm_kms_helper.ko which uncovered a misdesign in
how the whole thing was implemented. Let's revert all patches depending
on the bridge_state infrastructure for now.
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_bridge.c | 267 +----------------------------------
include/drm/drm_bridge.h | 124 ----------------
2 files changed, 1 insertion(+), 390 deletions(-)
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 37400607e9b7..8e4b799150b0 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -671,261 +671,13 @@ static int drm_atomic_bridge_check(struct drm_bridge *bridge,
return 0;
}
-/**
- * drm_atomic_helper_bridge_propagate_bus_fmt() - Propagate output format to
- * the input end of a bridge
- * @bridge: bridge control structure
- * @bridge_state: new bridge state
- * @crtc_state: new CRTC state
- * @conn_state: new connector state
- * @output_fmt: tested output bus format
- * @num_input_fmts: will contain the size of the returned array
- *
- * This helper is a pluggable implementation of the
- * &drm_bridge_funcs.atomic_get_input_bus_fmts operation for bridges that don't
- * modify the bus configuration between their input and their output. It
- * returns an array of input formats with a single element set to @output_fmt.
- *
- * RETURNS:
- * a valid format array of size @num_input_fmts, or NULL if the allocation
- * failed
- */
-u32 *
-drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
- struct drm_bridge_state *bridge_state,
- struct drm_crtc_state *crtc_state,
- struct drm_connector_state *conn_state,
- u32 output_fmt,
- unsigned int *num_input_fmts)
-{
- u32 *input_fmts;
-
- input_fmts = kzalloc(sizeof(*input_fmts), GFP_KERNEL);
- if (!input_fmts) {
- *num_input_fmts = 0;
- return NULL;
- }
-
- *num_input_fmts = 1;
- input_fmts[0] = output_fmt;
- return input_fmts;
-}
-EXPORT_SYMBOL(drm_atomic_helper_bridge_propagate_bus_fmt);
-
-static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
- struct drm_bridge *cur_bridge,
- struct drm_crtc_state *crtc_state,
- struct drm_connector_state *conn_state,
- u32 out_bus_fmt)
-{
- struct drm_bridge_state *cur_state;
- unsigned int num_in_bus_fmts, i;
- struct drm_bridge *prev_bridge;
- u32 *in_bus_fmts;
- int ret;
-
- prev_bridge = drm_bridge_get_prev_bridge(cur_bridge);
- cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,
- cur_bridge);
- if (WARN_ON(!cur_state))
- return -EINVAL;
-
- /*
- * If bus format negotiation is not supported by this bridge, let's
- * pass MEDIA_BUS_FMT_FIXED to the previous bridge in the chain and
- * hope that it can handle this situation gracefully (by providing
- * appropriate default values).
- */
- if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {
- if (cur_bridge != first_bridge) {
- ret = select_bus_fmt_recursive(first_bridge,
- prev_bridge, crtc_state,
- conn_state,
- MEDIA_BUS_FMT_FIXED);
- if (ret)
- return ret;
- }
-
- cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;
- cur_state->output_bus_cfg.format = out_bus_fmt;
- return 0;
- }
-
- in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,
- cur_state,
- crtc_state,
- conn_state,
- out_bus_fmt,
- &num_in_bus_fmts);
- if (!num_in_bus_fmts)
- return -ENOTSUPP;
- else if (!in_bus_fmts)
- return -ENOMEM;
-
- if (first_bridge == cur_bridge) {
- cur_state->input_bus_cfg.format = in_bus_fmts[0];
- cur_state->output_bus_cfg.format = out_bus_fmt;
- kfree(in_bus_fmts);
- return 0;
- }
-
- for (i = 0; i < num_in_bus_fmts; i++) {
- ret = select_bus_fmt_recursive(first_bridge, prev_bridge,
- crtc_state, conn_state,
- in_bus_fmts[i]);
- if (ret != -ENOTSUPP)
- break;
- }
-
- if (!ret) {
- cur_state->input_bus_cfg.format = in_bus_fmts[i];
- cur_state->output_bus_cfg.format = out_bus_fmt;
- }
-
- kfree(in_bus_fmts);
- return ret;
-}
-
-/*
- * This function is called by &drm_atomic_bridge_chain_check() just before
- * calling &drm_bridge_funcs.atomic_check() on all elements of the chain.
- * It performs bus format negotiation between bridge elements. The negotiation
- * happens in reverse order, starting from the last element in the chain up to
- * @bridge.
- *
- * Negotiation starts by retrieving supported output bus formats on the last
- * bridge element and testing them one by one. The test is recursive, meaning
- * that for each tested output format, the whole chain will be walked backward,
- * and each element will have to choose an input bus format that can be
- * transcoded to the requested output format. When a bridge element does not
- * support transcoding into a specific output format -ENOTSUPP is returned and
- * the next bridge element will have to try a different format. If none of the
- * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
- *
- * This implementation is relying on
- * &drm_bridge_funcs.atomic_get_output_bus_fmts() and
- * &drm_bridge_funcs.atomic_get_input_bus_fmts() to gather supported
- * input/output formats.
- *
- * When &drm_bridge_funcs.atomic_get_output_bus_fmts() is not implemented by
- * the last element of the chain, &drm_atomic_bridge_chain_select_bus_fmts()
- * tries a single format: &drm_connector.display_info.bus_formats[0] if
- * available, MEDIA_BUS_FMT_FIXED otherwise.
- *
- * When &drm_bridge_funcs.atomic_get_input_bus_fmts() is not implemented,
- * &drm_atomic_bridge_chain_select_bus_fmts() skips the negotiation on the
- * bridge element that lacks this hook and asks the previous element in the
- * chain to try MEDIA_BUS_FMT_FIXED. It's up to bridge drivers to decide what
- * to do in that case (fail if they want to enforce bus format negotiation, or
- * provide a reasonable default if they need to support pipelines where not
- * all elements support bus format negotiation).
- */
-static int
-drm_atomic_bridge_chain_select_bus_fmts(struct drm_bridge *bridge,
- struct drm_crtc_state *crtc_state,
- struct drm_connector_state *conn_state)
-{
- struct drm_connector *conn = conn_state->connector;
- struct drm_encoder *encoder = bridge->encoder;
- struct drm_bridge_state *last_bridge_state;
- unsigned int i, num_out_bus_fmts;
- struct drm_bridge *last_bridge;
- u32 *out_bus_fmts;
- int ret = 0;
-
- last_bridge = list_last_entry(&encoder->bridge_chain,
- struct drm_bridge, chain_node);
- last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
- last_bridge);
- if (WARN_ON(!last_bridge_state))
- return -EINVAL;
-
- if (last_bridge->funcs->atomic_get_output_bus_fmts) {
- const struct drm_bridge_funcs *funcs = last_bridge->funcs;
-
- out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,
- last_bridge_state,
- crtc_state,
- conn_state,
- &num_out_bus_fmts);
- if (!num_out_bus_fmts)
- return -ENOTSUPP;
- else if (!out_bus_fmts)
- return -ENOMEM;
- } else {
- num_out_bus_fmts = 1;
- out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL);
- if (!out_bus_fmts)
- return -ENOMEM;
-
- if (conn->display_info.num_bus_formats &&
- conn->display_info.bus_formats)
- out_bus_fmts[0] = conn->display_info.bus_formats[0];
- else
- out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;
- }
-
- for (i = 0; i < num_out_bus_fmts; i++) {
- ret = select_bus_fmt_recursive(bridge, last_bridge, crtc_state,
- conn_state, out_bus_fmts[i]);
- if (ret != -ENOTSUPP)
- break;
- }
-
- kfree(out_bus_fmts);
-
- return ret;
-}
-
-static void
-drm_atomic_bridge_propagate_bus_flags(struct drm_bridge *bridge,
- struct drm_connector *conn,
- struct drm_atomic_state *state)
-{
- struct drm_bridge_state *bridge_state, *next_bridge_state;
- struct drm_bridge *next_bridge;
- u32 output_flags;
-
- bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
- next_bridge = drm_bridge_get_next_bridge(bridge);
-
- /*
- * Let's try to apply the most common case here, that is, propagate
- * display_info flags for the last bridge, and propagate the input
- * flags of the next bridge element to the output end of the current
- * bridge when the bridge is not the last one.
- * There are exceptions to this rule, like when signal inversion is
- * happening at the board level, but that's something drivers can deal
- * with from their &drm_bridge_funcs.atomic_check() implementation by
- * simply overriding the flags value we've set here.
- */
- if (!next_bridge) {
- output_flags = conn->display_info.bus_flags;
- } else {
- next_bridge_state = drm_atomic_get_new_bridge_state(state,
- next_bridge);
- output_flags = next_bridge_state->input_bus_cfg.flags;
- }
-
- bridge_state->output_bus_cfg.flags = output_flags;
-
- /*
- * Propage the output flags to the input end of the bridge. Again, it's
- * not necessarily what all bridges want, but that's what most of them
- * do, and by doing that by default we avoid forcing drivers to
- * duplicate the "dummy propagation" logic.
- */
- bridge_state->input_bus_cfg.flags = output_flags;
-}
-
/**
* drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
* @bridge: bridge control structure
* @crtc_state: new CRTC state
* @conn_state: new connector state
*
- * First trigger a bus format negotiation before calling
- * &drm_bridge_funcs.atomic_check() (falls back on
+ * Calls &drm_bridge_funcs.atomic_check() (falls back on
* &drm_bridge_funcs.mode_fixup()) op for all the bridges in the encoder chain,
* starting from the last bridge to the first. These are called before calling
* &drm_encoder_helper_funcs.atomic_check()
@@ -937,29 +689,12 @@ int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
struct drm_crtc_state *crtc_state,
struct drm_connector_state *conn_state)
{
- struct drm_connector *conn = conn_state->connector;
struct drm_encoder *encoder = bridge->encoder;
struct drm_bridge *iter;
- int ret;
-
- ret = drm_atomic_bridge_chain_select_bus_fmts(bridge, crtc_state,
- conn_state);
- if (ret)
- return ret;
list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
int ret;
- /*
- * Bus flags are propagated by default. If a bridge needs to
- * tweak the input bus flags for any reason, it should happen
- * in its &drm_bridge_funcs.atomic_check() implementation such
- * that preceding bridges in the chain can propagate the new
- * bus flags.
- */
- drm_atomic_bridge_propagate_bus_flags(iter, conn,
- crtc_state->state);
-
ret = drm_atomic_bridge_check(iter, crtc_state, conn_state);
if (ret)
return ret;
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 46e15526b087..ae0595c70132 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -35,38 +35,6 @@ struct drm_bridge;
struct drm_bridge_timings;
struct drm_panel;
-/**
- * struct drm_bus_cfg - bus configuration
- *
- * This structure stores the configuration of a physical bus between two
- * components in an output pipeline, usually between two bridges, an encoder
- * and a bridge, or a bridge and a connector.
- *
- * The bus configuration is stored in &drm_bridge_state separately for the
- * input and output buses, as seen from the point of view of each bridge. The
- * bus configuration of a bridge output is usually identical to the
- * configuration of the next bridge's input, but may differ if the signals are
- * modified between the two bridges, for instance by an inverter on the board.
- * The input and output configurations of a bridge may differ if the bridge
- * modifies the signals internally, for instance by performing format
- * conversion, or modifying signals polarities.
- */
-struct drm_bus_cfg {
- /**
- * @format: format used on this bus (one of the MEDIA_BUS_FMT_* format)
- *
- * This field should not be directly modified by drivers
- * (&drm_atomic_bridge_chain_select_bus_fmts() takes care of the bus
- * format negotiation).
- */
- u32 format;
-
- /**
- * @flags: DRM_BUS_* flags used on this bus
- */
- u32 flags;
-};
-
/**
* struct drm_bridge_state - Atomic bridge state object
* @base: inherit from &drm_private_state
@@ -76,16 +44,6 @@ struct drm_bridge_state {
struct drm_private_state base;
struct drm_bridge *bridge;
-
- /**
- * @input_bus_cfg: input bus configuration
- */
- struct drm_bus_cfg input_bus_cfg;
-
- /**
- * @output_bus_cfg: input bus configuration
- */
- struct drm_bus_cfg output_bus_cfg;
};
static inline struct drm_bridge_state *
@@ -429,72 +387,6 @@ struct drm_bridge_funcs {
void (*atomic_destroy_state)(struct drm_bridge *bridge,
struct drm_bridge_state *state);
- /**
- * @atomic_get_output_bus_fmts:
- *
- * Return the supported bus formats on the output end of a bridge.
- * The returned array must be allocated with kmalloc() and will be
- * freed by the caller. If the allocation fails, NULL should be
- * returned. num_output_fmts must be set to the returned array size.
- * Formats listed in the returned array should be listed in decreasing
- * preference order (the core will try all formats until it finds one
- * that works).
- *
- * This method is only called on the last element of the bridge chain
- * as part of the bus format negotiation process that happens in
- * &drm_atomic_bridge_chain_select_bus_fmts().
- * This method is optional. When not implemented, the core will
- * fall back to &drm_connector.display_info.bus_formats[0] if
- * &drm_connector.display_info.num_bus_formats > 0,
- * or to MEDIA_BUS_FMT_FIXED otherwise.
- */
- u32 *(*atomic_get_output_bus_fmts)(struct drm_bridge *bridge,
- struct drm_bridge_state *bridge_state,
- struct drm_crtc_state *crtc_state,
- struct drm_connector_state *conn_state,
- unsigned int *num_output_fmts);
-
- /**
- * @atomic_get_input_bus_fmts:
- *
- * Return the supported bus formats on the input end of a bridge for
- * a specific output bus format.
- *
- * The returned array must be allocated with kmalloc() and will be
- * freed by the caller. If the allocation fails, NULL should be
- * returned. num_output_fmts must be set to the returned array size.
- * Formats listed in the returned array should be listed in decreasing
- * preference order (the core will try all formats until it finds one
- * that works). When the format is not supported NULL should be
- * returned and *num_output_fmts should be set to 0.
- *
- * This method is called on all elements of the bridge chain as part of
- * the bus format negotiation process that happens in
- * &drm_atomic_bridge_chain_select_bus_fmts().
- * This method is optional. When not implemented, the core will bypass
- * bus format negotiation on this element of the bridge without
- * failing, and the previous element in the chain will be passed
- * MEDIA_BUS_FMT_FIXED as its output bus format.
- *
- * Bridge drivers that need to support being linked to bridges that are
- * not supporting bus format negotiation should handle the
- * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a
- * sensible default value or extracting this information from somewhere
- * else (FW property, &drm_display_mode, &drm_display_info, ...)
- *
- * Note: Even if input format selection on the first bridge has no
- * impact on the negotiation process (bus format negotiation stops once
- * we reach the first element of the chain), drivers are expected to
- * return accurate input formats as the input format may be used to
- * configure the CRTC output appropriately.
- */
- u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge,
- struct drm_bridge_state *bridge_state,
- struct drm_crtc_state *crtc_state,
- struct drm_connector_state *conn_state,
- u32 output_fmt,
- unsigned int *num_input_fmts);
-
/**
* @atomic_check:
*
@@ -509,14 +401,6 @@ struct drm_bridge_funcs {
* called when &drm_bridge_funcs.atomic_check() is implemented, so only
* one of them should be provided.
*
- * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or
- * &drm_bridge_state.output_bus_cfg.flags it should should happen in
- * this function. By default the &drm_bridge_state.output_bus_cfg.flags
- * field is set to the next bridge
- * &drm_bridge_state.input_bus_cfg.flags value or
- * &drm_connector.display_info.bus_flags if the bridge is the last
- * element in the chain.
- *
* RETURNS:
* zero if the check passed, a negative error code otherwise.
*/
@@ -704,14 +588,6 @@ void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
struct drm_atomic_state *state);
-u32 *
-drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
- struct drm_bridge_state *bridge_state,
- struct drm_crtc_state *crtc_state,
- struct drm_connector_state *conn_state,
- u32 output_fmt,
- unsigned int *num_input_fmts);
-
void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
struct drm_bridge_state *state);
void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
--
2.23.0
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