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drm_probe_helper.c
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drm_probe_helper.c
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/*
* Copyright (c) 2006-2008 Intel Corporation
* Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
*
* DRM core CRTC related functions
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*
* Authors:
* Keith Packard
* Eric Anholt <eric@anholt.net>
* Dave Airlie <airlied@linux.ie>
* Jesse Barnes <jesse.barnes@intel.com>
*/
#include <linux/export.h>
#include <linux/moduleparam.h>
#include <drm/drm_bridge.h>
#include <drm/drm_client.h>
#include <drm/drm_crtc.h>
#include <drm/drm_edid.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_sysfs.h>
#include "drm_crtc_helper_internal.h"
/**
* DOC: output probing helper overview
*
* This library provides some helper code for output probing. It provides an
* implementation of the core &drm_connector_funcs.fill_modes interface with
* drm_helper_probe_single_connector_modes().
*
* It also provides support for polling connectors with a work item and for
* generic hotplug interrupt handling where the driver doesn't or cannot keep
* track of a per-connector hpd interrupt.
*
* This helper library can be used independently of the modeset helper library.
* Drivers can also overwrite different parts e.g. use their own hotplug
* handling code to avoid probing unrelated outputs.
*
* The probe helpers share the function table structures with other display
* helper libraries. See &struct drm_connector_helper_funcs for the details.
*/
static bool drm_kms_helper_poll = true;
module_param_named(poll, drm_kms_helper_poll, bool, 0600);
static enum drm_mode_status
drm_mode_validate_flag(const struct drm_display_mode *mode,
int flags)
{
if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
!(flags & DRM_MODE_FLAG_INTERLACE))
return MODE_NO_INTERLACE;
if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
!(flags & DRM_MODE_FLAG_DBLSCAN))
return MODE_NO_DBLESCAN;
if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
!(flags & DRM_MODE_FLAG_3D_MASK))
return MODE_NO_STEREO;
return MODE_OK;
}
static int
drm_mode_validate_pipeline(struct drm_display_mode *mode,
struct drm_connector *connector,
struct drm_modeset_acquire_ctx *ctx,
enum drm_mode_status *status)
{
struct drm_device *dev = connector->dev;
struct drm_encoder *encoder;
int ret;
/* Step 1: Validate against connector */
ret = drm_connector_mode_valid(connector, mode, ctx, status);
if (ret || *status != MODE_OK)
return ret;
/* Step 2: Validate against encoders and crtcs */
drm_connector_for_each_possible_encoder(connector, encoder) {
struct drm_bridge *bridge;
struct drm_crtc *crtc;
*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
* MODE_OK. */
continue;
}
bridge = drm_bridge_chain_get_first_bridge(encoder);
*status = drm_bridge_chain_mode_valid(bridge,
&connector->display_info,
mode);
if (*status != MODE_OK) {
/* There is also no point in continuing for crtc check
* here. */
continue;
}
drm_for_each_crtc(crtc, dev) {
if (!drm_encoder_crtc_ok(encoder, crtc))
continue;
*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 0;
}
}
}
return 0;
}
static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
{
struct drm_cmdline_mode *cmdline_mode;
struct drm_display_mode *mode;
cmdline_mode = &connector->cmdline_mode;
if (!cmdline_mode->specified)
return 0;
/* Only add a GTF mode if we find no matching probed modes */
list_for_each_entry(mode, &connector->probed_modes, head) {
if (mode->hdisplay != cmdline_mode->xres ||
mode->vdisplay != cmdline_mode->yres)
continue;
if (cmdline_mode->refresh_specified) {
/* The probed mode's vrefresh is set until later */
if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
continue;
}
/* Mark the matching mode as being preferred by the user */
mode->type |= DRM_MODE_TYPE_USERDEF;
return 0;
}
mode = drm_mode_create_from_cmdline_mode(connector->dev,
cmdline_mode);
if (mode == NULL)
return 0;
drm_mode_probed_add(connector, mode);
return 1;
}
enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
const struct drm_display_mode *mode)
{
const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
if (!crtc_funcs || !crtc_funcs->mode_valid)
return MODE_OK;
return crtc_funcs->mode_valid(crtc, mode);
}
enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
const struct drm_display_mode *mode)
{
const struct drm_encoder_helper_funcs *encoder_funcs =
encoder->helper_private;
if (!encoder_funcs || !encoder_funcs->mode_valid)
return MODE_OK;
return encoder_funcs->mode_valid(encoder, 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)
*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 ret;
}
static void drm_kms_helper_disable_hpd(struct drm_device *dev)
{
struct drm_connector *connector;
struct drm_connector_list_iter conn_iter;
drm_connector_list_iter_begin(dev, &conn_iter);
drm_for_each_connector_iter(connector, &conn_iter) {
const struct drm_connector_helper_funcs *funcs =
connector->helper_private;
if (funcs && funcs->disable_hpd)
funcs->disable_hpd(connector);
}
drm_connector_list_iter_end(&conn_iter);
}
static bool drm_kms_helper_enable_hpd(struct drm_device *dev)
{
bool poll = false;
struct drm_connector *connector;
struct drm_connector_list_iter conn_iter;
drm_connector_list_iter_begin(dev, &conn_iter);
drm_for_each_connector_iter(connector, &conn_iter) {
const struct drm_connector_helper_funcs *funcs =
connector->helper_private;
if (funcs && funcs->enable_hpd)
funcs->enable_hpd(connector);
if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
DRM_CONNECTOR_POLL_DISCONNECT))
poll = true;
}
drm_connector_list_iter_end(&conn_iter);
return poll;
}
#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
static void reschedule_output_poll_work(struct drm_device *dev)
{
unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
if (dev->mode_config.delayed_event)
/*
* FIXME:
*
* Use short (1s) delay to handle the initial delayed event.
* This delay should not be needed, but Optimus/nouveau will
* fail in a mysterious way if the delayed event is handled as
* soon as possible like it is done in
* drm_helper_probe_single_connector_modes() in case the poll
* was enabled before.
*/
delay = HZ;
schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
}
/**
* drm_kms_helper_poll_enable - re-enable output polling.
* @dev: drm_device
*
* This function re-enables the output polling work, after it has been
* temporarily disabled using drm_kms_helper_poll_disable(), for example over
* suspend/resume.
*
* Drivers can call this helper from their device resume implementation. It is
* not an error to call this even when output polling isn't enabled.
*
* If device polling was never initialized before, this call will trigger a
* warning and return.
*
* Note that calls to enable and disable polling must be strictly ordered, which
* is automatically the case when they're only call from suspend/resume
* callbacks.
*/
void drm_kms_helper_poll_enable(struct drm_device *dev)
{
if (drm_WARN_ON_ONCE(dev, !dev->mode_config.poll_enabled) ||
!drm_kms_helper_poll || dev->mode_config.poll_running)
return;
if (drm_kms_helper_enable_hpd(dev) ||
dev->mode_config.delayed_event)
reschedule_output_poll_work(dev);
dev->mode_config.poll_running = true;
}
EXPORT_SYMBOL(drm_kms_helper_poll_enable);
/**
* drm_kms_helper_poll_reschedule - reschedule the output polling work
* @dev: drm_device
*
* This function reschedules the output polling work, after polling for a
* connector has been enabled.
*
* Drivers must call this helper after enabling polling for a connector by
* setting %DRM_CONNECTOR_POLL_CONNECT / %DRM_CONNECTOR_POLL_DISCONNECT flags
* in drm_connector::polled. Note that after disabling polling by clearing these
* flags for a connector will stop the output polling work automatically if
* the polling is disabled for all other connectors as well.
*
* The function can be called only after polling has been enabled by calling
* drm_kms_helper_poll_init() / drm_kms_helper_poll_enable().
*/
void drm_kms_helper_poll_reschedule(struct drm_device *dev)
{
if (dev->mode_config.poll_running)
reschedule_output_poll_work(dev);
}
EXPORT_SYMBOL(drm_kms_helper_poll_reschedule);
static enum drm_connector_status
drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
{
const struct drm_connector_helper_funcs *funcs = connector->helper_private;
struct drm_modeset_acquire_ctx ctx;
int ret;
drm_modeset_acquire_init(&ctx, 0);
retry:
ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
if (!ret) {
if (funcs->detect_ctx)
ret = funcs->detect_ctx(connector, &ctx, force);
else if (connector->funcs->detect)
ret = connector->funcs->detect(connector, force);
else
ret = connector_status_connected;
}
if (ret == -EDEADLK) {
drm_modeset_backoff(&ctx);
goto retry;
}
if (WARN_ON(ret < 0))
ret = connector_status_unknown;
if (ret != connector->status)
connector->epoch_counter += 1;
drm_modeset_drop_locks(&ctx);
drm_modeset_acquire_fini(&ctx);
return ret;
}
/**
* drm_helper_probe_detect - probe connector status
* @connector: connector to probe
* @ctx: acquire_ctx, or NULL to let this function handle locking.
* @force: Whether destructive probe operations should be performed.
*
* This function calls the detect callbacks of the connector.
* This function returns &drm_connector_status, or
* if @ctx is set, it might also return -EDEADLK.
*/
int
drm_helper_probe_detect(struct drm_connector *connector,
struct drm_modeset_acquire_ctx *ctx,
bool force)
{
const struct drm_connector_helper_funcs *funcs = connector->helper_private;
struct drm_device *dev = connector->dev;
int ret;
if (!ctx)
return drm_helper_probe_detect_ctx(connector, force);
ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
if (ret)
return ret;
if (funcs->detect_ctx)
ret = funcs->detect_ctx(connector, ctx, force);
else if (connector->funcs->detect)
ret = connector->funcs->detect(connector, force);
else
ret = connector_status_connected;
if (ret != connector->status)
connector->epoch_counter += 1;
return ret;
}
EXPORT_SYMBOL(drm_helper_probe_detect);
static int drm_helper_probe_get_modes(struct drm_connector *connector)
{
const struct drm_connector_helper_funcs *connector_funcs =
connector->helper_private;
int count;
count = connector_funcs->get_modes(connector);
/* The .get_modes() callback should not return negative values. */
if (count < 0) {
drm_err(connector->dev, ".get_modes() returned %pe\n",
ERR_PTR(count));
count = 0;
}
/*
* Fallback for when DDC probe failed in drm_get_edid() and thus skipped
* override/firmware EDID.
*/
if (count == 0 && connector->status == connector_status_connected)
count = drm_edid_override_connector_update(connector);
return count;
}
static int __drm_helper_update_and_validate(struct drm_connector *connector,
uint32_t maxX, uint32_t maxY,
struct drm_modeset_acquire_ctx *ctx)
{
struct drm_device *dev = connector->dev;
struct drm_display_mode *mode;
int mode_flags = 0;
int ret;
drm_connector_list_update(connector);
if (connector->interlace_allowed)
mode_flags |= DRM_MODE_FLAG_INTERLACE;
if (connector->doublescan_allowed)
mode_flags |= DRM_MODE_FLAG_DBLSCAN;
if (connector->stereo_allowed)
mode_flags |= DRM_MODE_FLAG_3D_MASK;
list_for_each_entry(mode, &connector->modes, head) {
if (mode->status != MODE_OK)
continue;
mode->status = drm_mode_validate_driver(dev, mode);
if (mode->status != MODE_OK)
continue;
mode->status = drm_mode_validate_size(mode, maxX, maxY);
if (mode->status != MODE_OK)
continue;
mode->status = drm_mode_validate_flag(mode, mode_flags);
if (mode->status != MODE_OK)
continue;
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
return -EDEADLK;
}
if (mode->status != MODE_OK)
continue;
mode->status = drm_mode_validate_ycbcr420(mode, connector);
}
return 0;
}
/**
* drm_helper_probe_single_connector_modes - get complete set of display modes
* @connector: connector to probe
* @maxX: max width for modes
* @maxY: max height for modes
*
* Based on the helper callbacks implemented by @connector in struct
* &drm_connector_helper_funcs try to detect all valid modes. Modes will first
* be added to the connector's probed_modes list, then culled (based on validity
* and the @maxX, @maxY parameters) and put into the normal modes list.
*
* Intended to be used as a generic implementation of the
* &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
* for output mode filtering and detection.
*
* The basic procedure is as follows
*
* 1. All modes currently on the connector's modes list are marked as stale
*
* 2. New modes are added to the connector's probed_modes list with
* drm_mode_probed_add(). New modes start their life with status as OK.
* Modes are added from a single source using the following priority order.
*
* - &drm_connector_helper_funcs.get_modes vfunc
* - if the connector status is connector_status_connected, standard
* VESA DMT modes up to 1024x768 are automatically added
* (drm_add_modes_noedid())
*
* Finally modes specified via the kernel command line (video=...) are
* added in addition to what the earlier probes produced
* (drm_helper_probe_add_cmdline_mode()). These modes are generated
* using the VESA GTF/CVT formulas.
*
* 3. Modes are moved from the probed_modes list to the modes list. Potential
* duplicates are merged together (see drm_connector_list_update()).
* After this step the probed_modes list will be empty again.
*
* 4. Any non-stale mode on the modes list then undergoes validation
*
* - drm_mode_validate_basic() performs basic sanity checks
* - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
* (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 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
* enforced by the modeset/atomic helpers
*
* 5. Any mode whose status is not OK is pruned from the connector's modes list,
* accompanied by a debug message indicating the reason for the mode's
* rejection (see drm_mode_prune_invalid()).
*
* Returns:
* The number of modes found on @connector.
*/
int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
uint32_t maxX, uint32_t maxY)
{
struct drm_device *dev = connector->dev;
struct drm_display_mode *mode;
int count = 0, ret;
enum drm_connector_status old_status;
struct drm_modeset_acquire_ctx ctx;
WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
drm_modeset_acquire_init(&ctx, 0);
DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
connector->name);
retry:
ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
if (ret == -EDEADLK) {
drm_modeset_backoff(&ctx);
goto retry;
} else
WARN_ON(ret < 0);
/* set all old modes to the stale state */
list_for_each_entry(mode, &connector->modes, head)
mode->status = MODE_STALE;
old_status = connector->status;
if (connector->force) {
if (connector->force == DRM_FORCE_ON ||
connector->force == DRM_FORCE_ON_DIGITAL)
connector->status = connector_status_connected;
else
connector->status = connector_status_disconnected;
if (connector->funcs->force)
connector->funcs->force(connector);
} else {
ret = drm_helper_probe_detect(connector, &ctx, true);
if (ret == -EDEADLK) {
drm_modeset_backoff(&ctx);
goto retry;
} else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
ret = connector_status_unknown;
connector->status = ret;
}
/*
* Normally either the driver's hpd code or the poll loop should
* pick up any changes and fire the hotplug event. But if
* userspace sneaks in a probe, we might miss a change. Hence
* check here, and if anything changed start the hotplug code.
*/
if (old_status != connector->status) {
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
connector->base.id,
connector->name,
drm_get_connector_status_name(old_status),
drm_get_connector_status_name(connector->status));
/*
* The hotplug event code might call into the fb
* helpers, and so expects that we do not hold any
* locks. Fire up the poll struct instead, it will
* disable itself again.
*/
dev->mode_config.delayed_event = true;
if (dev->mode_config.poll_enabled)
mod_delayed_work(system_wq,
&dev->mode_config.output_poll_work,
0);
}
/*
* Re-enable polling in case the global poll config changed but polling
* is still initialized.
*/
if (dev->mode_config.poll_enabled)
drm_kms_helper_poll_enable(dev);
if (connector->status == connector_status_disconnected) {
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
connector->base.id, connector->name);
drm_connector_update_edid_property(connector, NULL);
drm_mode_prune_invalid(dev, &connector->modes, false);
goto exit;
}
count = drm_helper_probe_get_modes(connector);
if (count == 0 && (connector->status == connector_status_connected ||
connector->status == connector_status_unknown)) {
count = drm_add_modes_noedid(connector, 1024, 768);
/*
* Section 4.2.2.6 (EDID Corruption Detection) of the DP 1.4a
* Link CTS specifies that 640x480 (the official "failsafe"
* mode) needs to be the default if there's no EDID.
*/
if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort)
drm_set_preferred_mode(connector, 640, 480);
}
count += drm_helper_probe_add_cmdline_mode(connector);
if (count != 0) {
ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
if (ret == -EDEADLK) {
drm_modeset_backoff(&ctx);
goto retry;
}
}
drm_mode_prune_invalid(dev, &connector->modes, true);
/*
* Displayport spec section 5.2.1.2 ("Video Timing Format") says that
* all detachable sinks shall support 640x480 @60Hz as a fail safe
* mode. If all modes were pruned, perhaps because they need more
* lanes or a higher pixel clock than available, at least try to add
* in 640x480.
*/
if (list_empty(&connector->modes) &&
connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
count = drm_add_modes_noedid(connector, 640, 480);
ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
if (ret == -EDEADLK) {
drm_modeset_backoff(&ctx);
goto retry;
}
drm_mode_prune_invalid(dev, &connector->modes, true);
}
exit:
drm_modeset_drop_locks(&ctx);
drm_modeset_acquire_fini(&ctx);
if (list_empty(&connector->modes))
return 0;
drm_mode_sort(&connector->modes);
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
connector->name);
list_for_each_entry(mode, &connector->modes, head) {
drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
drm_mode_debug_printmodeline(mode);
}
return count;
}
EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
/**
* drm_kms_helper_hotplug_event - fire off KMS hotplug events
* @dev: drm_device whose connector state changed
*
* This function fires off the uevent for userspace and also calls the
* output_poll_changed function, which is most commonly used to inform the fbdev
* emulation code and allow it to update the fbcon output configuration.
*
* Drivers should call this from their hotplug handling code when a change is
* detected. Note that this function does not do any output detection of its
* own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
* driver already.
*
* This function must be called from process context with no mode
* setting locks held.
*
* If only a single connector has changed, consider calling
* drm_kms_helper_connector_hotplug_event() instead.
*/
void drm_kms_helper_hotplug_event(struct drm_device *dev)
{
/* send a uevent + call fbdev */
drm_sysfs_hotplug_event(dev);
if (dev->mode_config.funcs->output_poll_changed)
dev->mode_config.funcs->output_poll_changed(dev);
drm_client_dev_hotplug(dev);
}
EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
/**
* drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event
* @connector: drm_connector which has changed
*
* This is the same as drm_kms_helper_hotplug_event(), except it fires a more
* fine-grained uevent for a single connector.
*/
void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector)
{
struct drm_device *dev = connector->dev;
/* send a uevent + call fbdev */
drm_sysfs_connector_hotplug_event(connector);
if (dev->mode_config.funcs->output_poll_changed)
dev->mode_config.funcs->output_poll_changed(dev);
drm_client_dev_hotplug(dev);
}
EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event);
static void output_poll_execute(struct work_struct *work)
{
struct delayed_work *delayed_work = to_delayed_work(work);
struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
struct drm_connector *connector;
struct drm_connector_list_iter conn_iter;
enum drm_connector_status old_status;
bool repoll = false, changed;
u64 old_epoch_counter;
if (!dev->mode_config.poll_enabled)
return;
/* Pick up any changes detected by the probe functions. */
changed = dev->mode_config.delayed_event;
dev->mode_config.delayed_event = false;
if (!drm_kms_helper_poll) {
if (dev->mode_config.poll_running) {
drm_kms_helper_disable_hpd(dev);
dev->mode_config.poll_running = false;
}
goto out;
}
if (!mutex_trylock(&dev->mode_config.mutex)) {
repoll = true;
goto out;
}
drm_connector_list_iter_begin(dev, &conn_iter);
drm_for_each_connector_iter(connector, &conn_iter) {
/* Ignore forced connectors. */
if (connector->force)
continue;
/* Ignore HPD capable connectors and connectors where we don't
* want any hotplug detection at all for polling. */
if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
continue;
old_status = connector->status;
/* if we are connected and don't want to poll for disconnect
skip it */
if (old_status == connector_status_connected &&
!(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
continue;
repoll = true;
old_epoch_counter = connector->epoch_counter;
connector->status = drm_helper_probe_detect(connector, NULL, false);
if (old_epoch_counter != connector->epoch_counter) {
const char *old, *new;
/*
* The poll work sets force=false when calling detect so
* that drivers can avoid to do disruptive tests (e.g.
* when load detect cycles could cause flickering on
* other, running displays). This bears the risk that we
* flip-flop between unknown here in the poll work and
* the real state when userspace forces a full detect
* call after receiving a hotplug event due to this
* change.
*
* Hence clamp an unknown detect status to the old
* value.
*/
if (connector->status == connector_status_unknown) {
connector->status = old_status;
continue;
}
old = drm_get_connector_status_name(old_status);
new = drm_get_connector_status_name(connector->status);
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
"status updated from %s to %s\n",
connector->base.id,
connector->name,
old, new);
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
connector->base.id, connector->name,
old_epoch_counter, connector->epoch_counter);
changed = true;
}
}
drm_connector_list_iter_end(&conn_iter);
mutex_unlock(&dev->mode_config.mutex);
out:
if (changed)
drm_kms_helper_hotplug_event(dev);
if (repoll)
schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
}
/**
* drm_kms_helper_is_poll_worker - is %current task an output poll worker?
*
* Determine if %current task is an output poll worker. This can be used
* to select distinct code paths for output polling versus other contexts.
*
* One use case is to avoid a deadlock between the output poll worker and
* the autosuspend worker wherein the latter waits for polling to finish
* upon calling drm_kms_helper_poll_disable(), while the former waits for
* runtime suspend to finish upon calling pm_runtime_get_sync() in a
* connector ->detect hook.
*/
bool drm_kms_helper_is_poll_worker(void)
{
struct work_struct *work = current_work();
return work && work->func == output_poll_execute;
}
EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
/**
* drm_kms_helper_poll_disable - disable output polling
* @dev: drm_device
*
* This function disables the output polling work.
*
* Drivers can call this helper from their device suspend implementation. It is
* not an error to call this even when output polling isn't enabled or already
* disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
*
* If however, the polling was never initialized, this call will trigger a
* warning and return
*
* Note that calls to enable and disable polling must be strictly ordered, which
* is automatically the case when they're only call from suspend/resume
* callbacks.
*/
void drm_kms_helper_poll_disable(struct drm_device *dev)
{
if (drm_WARN_ON(dev, !dev->mode_config.poll_enabled))
return;
if (dev->mode_config.poll_running)
drm_kms_helper_disable_hpd(dev);
cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
dev->mode_config.poll_running = false;
}
EXPORT_SYMBOL(drm_kms_helper_poll_disable);
/**
* drm_kms_helper_poll_init - initialize and enable output polling
* @dev: drm_device
*
* This function initializes and then also enables output polling support for
* @dev. Drivers which do not have reliable hotplug support in hardware can use
* this helper infrastructure to regularly poll such connectors for changes in
* their connection state.
*
* Drivers can control which connectors are polled by setting the
* DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
* connectors where probing live outputs can result in visual distortion drivers
* should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
* Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
* completely ignored by the polling logic.
*
* Note that a connector can be both polled and probed from the hotplug handler,
* in case the hotplug interrupt is known to be unreliable.
*/
void drm_kms_helper_poll_init(struct drm_device *dev)
{
INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
dev->mode_config.poll_enabled = true;
drm_kms_helper_poll_enable(dev);
}
EXPORT_SYMBOL(drm_kms_helper_poll_init);
/**
* drm_kms_helper_poll_fini - disable output polling and clean it up
* @dev: drm_device
*/
void drm_kms_helper_poll_fini(struct drm_device *dev)
{
if (!dev->mode_config.poll_enabled)
return;
drm_kms_helper_poll_disable(dev);
dev->mode_config.poll_enabled = false;
}
EXPORT_SYMBOL(drm_kms_helper_poll_fini);
static bool check_connector_changed(struct drm_connector *connector)
{
struct drm_device *dev = connector->dev;
enum drm_connector_status old_status;
u64 old_epoch_counter;
/* Only handle HPD capable connectors. */
drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD));
drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex));
old_status = connector->status;
old_epoch_counter = connector->epoch_counter;
connector->status = drm_helper_probe_detect(connector, NULL, false);
if (old_epoch_counter == connector->epoch_counter) {
drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Same epoch counter %llu\n",
connector->base.id,
connector->name,
connector->epoch_counter);
return false;
}
drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
connector->base.id,
connector->name,
drm_get_connector_status_name(old_status),
drm_get_connector_status_name(connector->status));
drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n",
connector->base.id,
connector->name,
old_epoch_counter,
connector->epoch_counter);
return true;
}
/**
* drm_connector_helper_hpd_irq_event - hotplug processing
* @connector: drm_connector
*
* Drivers can use this helper function to run a detect cycle on a connector
* which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member.
*
* This helper function is useful for drivers which can track hotplug