drm/probe_helper: Add drm_connector_helper_funcs.mode_valid_ctx

This is just an atomic version of mode_valid, which is intended to be
used for situations where a driver might need to check the atomic state
of objects other than the connector itself. One such example is with
MST, where the maximum possible bandwidth on a connector can change
dynamically irregardless of the display configuration.

Changes since v1:
* Use new drm logging functions
* Make some corrections in the mode_valid_ctx kdoc
* Return error codes or 0 from ->mode_valid_ctx() on fail, and store the
  drm_mode_status in an additional function parameter
Changes since v2:
* Don't accidentally assign ret to mode->status on success, or we'll
  squash legitimate mode validation results
* Don't forget to assign MODE_OK to status in drm_connector_mode_valid()
  if we have no callbacks
* Drop leftover hunk in drm_modes.h around enum drm_mode_status
Changes since v3:
* s/return ret/return 0/ in drm_mode_validate_pipeline()
* Minor cleanup in drm_connector_mode_valid()

Tested-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Cc: Lee Shawn C <shawn.c.lee@intel.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200713170746.254388-2-lyude@redhat.com
This commit is contained in:
Lyude Paul 2020-07-13 13:07:45 -04:00
parent 1d9221e9d3
commit 1c26b8e090
3 changed files with 110 additions and 34 deletions

View File

@ -73,8 +73,11 @@ enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
const struct drm_display_mode *mode);
enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
const struct drm_display_mode *mode);
enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector,
struct drm_display_mode *mode);
int
drm_connector_mode_valid(struct drm_connector *connector,
struct drm_display_mode *mode,
struct drm_modeset_acquire_ctx *ctx,
enum drm_mode_status *status);
struct drm_encoder *
drm_connector_get_single_encoder(struct drm_connector *connector);

View File

@ -86,17 +86,19 @@ drm_mode_validate_flag(const struct drm_display_mode *mode,
return MODE_OK;
}
static enum drm_mode_status
static int
drm_mode_validate_pipeline(struct drm_display_mode *mode,
struct drm_connector *connector)
struct drm_connector *connector,
struct drm_modeset_acquire_ctx *ctx,
enum drm_mode_status *status)
{
struct drm_device *dev = connector->dev;
enum drm_mode_status ret = MODE_OK;
struct drm_encoder *encoder;
int ret;
/* Step 1: Validate against connector */
ret = drm_connector_mode_valid(connector, mode);
if (ret != MODE_OK)
ret = drm_connector_mode_valid(connector, mode, ctx, status);
if (ret || *status != MODE_OK)
return ret;
/* Step 2: Validate against encoders and crtcs */
@ -104,8 +106,8 @@ drm_mode_validate_pipeline(struct drm_display_mode *mode,
struct drm_bridge *bridge;
struct drm_crtc *crtc;
ret = drm_encoder_mode_valid(encoder, mode);
if (ret != MODE_OK) {
*status = drm_encoder_mode_valid(encoder, mode);
if (*status != MODE_OK) {
/* No point in continuing for crtc check as this encoder
* will not accept the mode anyway. If all encoders
* reject the mode then, at exit, ret will not be
@ -114,8 +116,8 @@ drm_mode_validate_pipeline(struct drm_display_mode *mode,
}
bridge = drm_bridge_chain_get_first_bridge(encoder);
ret = drm_bridge_chain_mode_valid(bridge, mode);
if (ret != MODE_OK) {
*status = drm_bridge_chain_mode_valid(bridge, mode);
if (*status != MODE_OK) {
/* There is also no point in continuing for crtc check
* here. */
continue;
@ -125,17 +127,17 @@ drm_mode_validate_pipeline(struct drm_display_mode *mode,
if (!drm_encoder_crtc_ok(encoder, crtc))
continue;
ret = drm_crtc_mode_valid(crtc, mode);
if (ret == MODE_OK) {
*status = drm_crtc_mode_valid(crtc, mode);
if (*status == MODE_OK) {
/* If we get to this point there is at least
* one combination of encoder+crtc that works
* for this mode. Lets return now. */
return ret;
return 0;
}
}
}
return ret;
return 0;
}
static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
@ -196,16 +198,27 @@ enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
return encoder_funcs->mode_valid(encoder, mode);
}
enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector,
struct drm_display_mode *mode)
int
drm_connector_mode_valid(struct drm_connector *connector,
struct drm_display_mode *mode,
struct drm_modeset_acquire_ctx *ctx,
enum drm_mode_status *status)
{
const struct drm_connector_helper_funcs *connector_funcs =
connector->helper_private;
int ret = 0;
if (!connector_funcs || !connector_funcs->mode_valid)
return MODE_OK;
if (!connector_funcs)
*status = MODE_OK;
else if (connector_funcs->mode_valid_ctx)
ret = connector_funcs->mode_valid_ctx(connector, mode, ctx,
status);
else if (connector_funcs->mode_valid)
*status = connector_funcs->mode_valid(connector, mode);
else
*status = MODE_OK;
return connector_funcs->mode_valid(connector, mode);
return ret;
}
#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
@ -375,8 +388,9 @@ EXPORT_SYMBOL(drm_helper_probe_detect);
* (if specified)
* - drm_mode_validate_flag() checks the modes against basic connector
* capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
* - the optional &drm_connector_helper_funcs.mode_valid helper can perform
* driver and/or sink specific checks
* - the optional &drm_connector_helper_funcs.mode_valid or
* &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver
* and/or sink specific checks
* - the optional &drm_crtc_helper_funcs.mode_valid,
* &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
* helpers can perform driver and/or source specific checks which are also
@ -507,22 +521,39 @@ retry:
mode_flags |= DRM_MODE_FLAG_3D_MASK;
list_for_each_entry(mode, &connector->modes, head) {
if (mode->status == MODE_OK)
mode->status = drm_mode_validate_driver(dev, mode);
if (mode->status != MODE_OK)
continue;
if (mode->status == MODE_OK)
mode->status = drm_mode_validate_size(mode, maxX, maxY);
mode->status = drm_mode_validate_driver(dev, mode);
if (mode->status != MODE_OK)
continue;
if (mode->status == MODE_OK)
mode->status = drm_mode_validate_flag(mode, mode_flags);
mode->status = drm_mode_validate_size(mode, maxX, maxY);
if (mode->status != MODE_OK)
continue;
if (mode->status == MODE_OK)
mode->status = drm_mode_validate_pipeline(mode,
connector);
mode->status = drm_mode_validate_flag(mode, mode_flags);
if (mode->status != MODE_OK)
continue;
if (mode->status == MODE_OK)
mode->status = drm_mode_validate_ycbcr420(mode,
connector);
ret = drm_mode_validate_pipeline(mode, connector, &ctx,
&mode->status);
if (ret) {
drm_dbg_kms(dev,
"drm_mode_validate_pipeline failed: %d\n",
ret);
if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK)) {
mode->status = MODE_ERROR;
} else {
drm_modeset_backoff(&ctx);
goto retry;
}
}
if (mode->status != MODE_OK)
continue;
mode->status = drm_mode_validate_ycbcr420(mode, connector);
}
prune:

View File

@ -968,6 +968,48 @@ struct drm_connector_helper_funcs {
*/
enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
struct drm_display_mode *mode);
/**
* @mode_valid_ctx:
*
* Callback to validate a mode for a connector, irrespective of the
* specific display configuration.
*
* This callback is used by the probe helpers to filter the mode list
* (which is usually derived from the EDID data block from the sink).
* See e.g. drm_helper_probe_single_connector_modes().
*
* This function is optional, and is the atomic version of
* &drm_connector_helper_funcs.mode_valid.
*
* To allow for accessing the atomic state of modesetting objects, the
* helper libraries always call this with ctx set to a valid context,
* and &drm_mode_config.connection_mutex will always be locked with
* the ctx parameter set to @ctx. This allows for taking additional
* locks as required.
*
* Even though additional locks may be acquired, this callback is
* still expected not to take any constraints into account which would
* be influenced by the currently set display state - such constraints
* should be handled in the driver's atomic check. For example, if a
* connector shares display bandwidth with other connectors then it
* would be ok to validate the minimum bandwidth requirement of a mode
* against the maximum possible bandwidth of the connector. But it
* wouldn't be ok to take the current bandwidth usage of other
* connectors into account, as this would change depending on the
* display state.
*
* Returns:
* 0 if &drm_connector_helper_funcs.mode_valid_ctx succeeded and wrote
* the &enum drm_mode_status value to @status, or a negative error
* code otherwise.
*
*/
int (*mode_valid_ctx)(struct drm_connector *connector,
struct drm_display_mode *mode,
struct drm_modeset_acquire_ctx *ctx,
enum drm_mode_status *status);
/**
* @best_encoder:
*