diff options
author | 2020-01-07 19:58:04 +0100 | |
---|---|---|
committer | 2020-01-08 00:33:55 +0100 | |
commit | 3dfbf2d3d05eccb0d4ffb4f30467519e601a5db6 (patch) | |
tree | dfebd5f661dc7360ffd01b7df058eba855080997 /drivers/gpu/drm/drm_bridge.c | |
parent | Revert "drm/bridge: Fix a NULL pointer dereference in drm_atomic_bridge_chain... (diff) | |
download | linux-3dfbf2d3d05eccb0d4ffb4f30467519e601a5db6.tar.gz linux-3dfbf2d3d05eccb0d4ffb4f30467519e601a5db6.tar.bz2 linux-3dfbf2d3d05eccb0d4ffb4f30467519e601a5db6.zip |
Revert "drm/bridge: Add the necessary bits to support bus format negotiation"
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@collabora.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200107185807.606999-3-boris.brezillon@collabora.com
Diffstat (limited to 'drivers/gpu/drm/drm_bridge.c')
-rw-r--r-- | drivers/gpu/drm/drm_bridge.c | 267 |
1 files changed, 1 insertions, 266 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 @@ -672,260 +672,12 @@ static int drm_atomic_bridge_check(struct drm_bridge *bridge, } /** - * 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; |