[Intel-gfx] [PATCH] drm/atomic: Acquire connection_mutex lock in drm_helper_probe_single_connector_modes.
Maarten Lankhorst
maarten.lankhorst at linux.intel.com
Wed Mar 29 10:16:50 UTC 2017
mode_valid() and get_modes() called
from drm_helper_probe_single_connector_modes()
may need to look at connector->state because what a valid mode is may
depend on connector properties being set. For example some HDMI modes
might be rejected when a connector property forces the connector
into DVI mode.
Some implementations of detect() already lock all state,
so we have to pass an acquire_ctx to them to prevent a deadlock.
This means changing the function signature of detect() slightly,
and passing the acquire_ctx for locking multiple crtc's.
It might be NULL, in which case expensive operations should be avoided.
intel_dp.c however ignores the force flag, so still lock
connection_mutex there if needed.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Boris Brezillon <boris.brezillon at free-electrons.com>
Cc: Manasi Navare <manasi.d.navare at intel.com>
---
drivers/gpu/drm/drm_probe_helper.c | 41 ++++++++++++++++++++++++++++++------
drivers/gpu/drm/i915/intel_crt.c | 29 +++++++++++++------------
drivers/gpu/drm/i915/intel_display.c | 25 +++++++++++-----------
drivers/gpu/drm/i915/intel_dp.c | 22 ++++++++++++-------
drivers/gpu/drm/i915/intel_drv.h | 8 +++----
drivers/gpu/drm/i915/intel_hotplug.c | 6 +++++-
drivers/gpu/drm/i915/intel_tv.c | 24 ++++++++++-----------
include/drm/drm_connector.h | 5 +++++
8 files changed, 101 insertions(+), 59 deletions(-)
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 85005d57bde6..a48cff963871 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -169,11 +169,15 @@ void drm_kms_helper_poll_enable(struct drm_device *dev)
EXPORT_SYMBOL(drm_kms_helper_poll_enable);
static enum drm_connector_status
-drm_connector_detect(struct drm_connector *connector, bool force)
+drm_connector_detect(struct drm_connector *connector,
+ struct drm_modeset_acquire_ctx *ctx)
{
- return connector->funcs->detect ?
- connector->funcs->detect(connector, force) :
- connector_status_connected;
+ if (connector->funcs->detect_ctx)
+ return connector->funcs->detect_ctx(connector, ctx);
+ else if (connector->funcs->detect)
+ return connector->funcs->detect(connector, !!ctx);
+ else
+ return connector_status_connected;
}
/**
@@ -239,15 +243,27 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
struct drm_display_mode *mode;
const struct drm_connector_helper_funcs *connector_funcs =
connector->helper_private;
- int count = 0;
+ int count = 0, ret;
int mode_flags = 0;
bool verbose_prune = true;
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;
@@ -263,7 +279,15 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
if (connector->funcs->force)
connector->funcs->force(connector);
} else {
- connector->status = drm_connector_detect(connector, true);
+ ret = drm_connector_detect(connector, &ctx);
+
+ 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;
}
/*
@@ -355,6 +379,9 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
prune:
drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
+ drm_modeset_drop_locks(&ctx);
+ drm_modeset_acquire_fini(&ctx);
+
if (list_empty(&connector->modes))
return 0;
@@ -440,7 +467,7 @@ static void output_poll_execute(struct work_struct *work)
repoll = true;
- connector->status = drm_connector_detect(connector, false);
+ connector->status = drm_connector_detect(connector, NULL);
if (old_status != connector->status) {
const char *old, *new;
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 8c82607294c6..1186c3f5fea0 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -669,19 +669,19 @@ static const struct dmi_system_id intel_spurious_crt_detect[] = {
{ }
};
-static enum drm_connector_status
-intel_crt_detect(struct drm_connector *connector, bool force)
+static int
+intel_crt_detect(struct drm_connector *connector,
+ struct drm_modeset_acquire_ctx *ctx)
{
struct drm_i915_private *dev_priv = to_i915(connector->dev);
struct intel_crt *crt = intel_attached_crt(connector);
struct intel_encoder *intel_encoder = &crt->base;
- enum drm_connector_status status;
+ int status, ret;
struct intel_load_detect_pipe tmp;
- struct drm_modeset_acquire_ctx ctx;
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force=%d\n",
connector->base.id, connector->name,
- force);
+ !!ctx);
/* Skip machines without VGA that falsely report hotplug events */
if (dmi_check_system(intel_spurious_crt_detect))
@@ -716,15 +716,19 @@ intel_crt_detect(struct drm_connector *connector, bool force)
goto out;
}
- if (!force) {
+ if (!ctx) {
status = connector->status;
goto out;
}
- drm_modeset_acquire_init(&ctx, 0);
-
/* for pre-945g platforms use load detect */
- if (intel_get_load_detect_pipe(connector, NULL, &tmp, &ctx)) {
+ ret = intel_get_load_detect_pipe(connector, NULL, &tmp, ctx);
+ if (ret < 0) {
+ status = ret;
+ goto out;
+ }
+
+ if (ret > 0) {
if (intel_crt_detect_ddc(connector))
status = connector_status_connected;
else if (INTEL_GEN(dev_priv) < 4)
@@ -734,13 +738,10 @@ intel_crt_detect(struct drm_connector *connector, bool force)
status = connector_status_disconnected;
else
status = connector_status_unknown;
- intel_release_load_detect_pipe(connector, &tmp, &ctx);
+ intel_release_load_detect_pipe(connector, &tmp, ctx);
} else
status = connector_status_unknown;
- drm_modeset_drop_locks(&ctx);
- drm_modeset_acquire_fini(&ctx);
-
out:
intel_display_power_put(dev_priv, intel_encoder->power_domain);
return status;
@@ -811,7 +812,7 @@ void intel_crt_reset(struct drm_encoder *encoder)
static const struct drm_connector_funcs intel_crt_connector_funcs = {
.dpms = drm_atomic_helper_connector_dpms,
- .detect = intel_crt_detect,
+ .detect_ctx = intel_crt_detect,
.fill_modes = drm_helper_probe_single_connector_modes,
.late_register = intel_connector_register,
.early_unregister = intel_connector_unregister,
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a79063fac951..baa8d836c8e7 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9503,10 +9503,10 @@ static int intel_modeset_setup_plane_state(struct drm_atomic_state *state,
return 0;
}
-bool intel_get_load_detect_pipe(struct drm_connector *connector,
- struct drm_display_mode *mode,
- struct intel_load_detect_pipe *old,
- struct drm_modeset_acquire_ctx *ctx)
+int intel_get_load_detect_pipe(struct drm_connector *connector,
+ struct drm_display_mode *mode,
+ struct intel_load_detect_pipe *old,
+ struct drm_modeset_acquire_ctx *ctx)
{
struct intel_crtc *intel_crtc;
struct intel_encoder *intel_encoder =
@@ -9529,10 +9529,7 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
old->restore_state = NULL;
-retry:
- ret = drm_modeset_lock(&config->connection_mutex, ctx);
- if (ret)
- goto fail;
+ WARN_ON(!drm_modeset_is_locked(&config->connection_mutex));
/*
* Algorithm gets a little messy:
@@ -9682,10 +9679,8 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
restore_state = NULL;
}
- if (ret == -EDEADLK) {
- drm_modeset_backoff(ctx);
- goto retry;
- }
+ if (ret == -EDEADLK)
+ return ret;
return false;
}
@@ -15112,6 +15107,7 @@ static void intel_enable_pipe_a(struct drm_device *dev)
struct drm_connector *crt = NULL;
struct intel_load_detect_pipe load_detect_temp;
struct drm_modeset_acquire_ctx *ctx = dev->mode_config.acquire_ctx;
+ int ret;
/* We can't just switch on the pipe A, we need to set things up with a
* proper mode and output configuration. As a gross hack, enable pipe A
@@ -15128,7 +15124,10 @@ static void intel_enable_pipe_a(struct drm_device *dev)
if (!crt)
return;
- if (intel_get_load_detect_pipe(crt, NULL, &load_detect_temp, ctx))
+ ret = intel_get_load_detect_pipe(crt, NULL, &load_detect_temp, ctx);
+ WARN(ret < 0, "All modeset mutexes are locked, but intel_get_load_detect_pipe failed\n");
+
+ if (ret > 0)
intel_release_load_detect_pipe(crt, &load_detect_temp, ctx);
}
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index fd96a6cf7326..10b3727b7381 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4567,7 +4567,8 @@ intel_dp_unset_edid(struct intel_dp *intel_dp)
}
static enum drm_connector_status
-intel_dp_long_pulse(struct intel_connector *intel_connector)
+intel_dp_long_pulse(struct intel_connector *intel_connector,
+ struct drm_modeset_acquire_ctx *ctx)
{
struct drm_connector *connector = &intel_connector->base;
struct intel_dp *intel_dp = intel_attached_dp(connector);
@@ -4640,9 +4641,13 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
* check links status, there has been known issues of
* link loss triggerring long pulse!!!!
*/
- drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+ if (!ctx)
+ drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+
intel_dp_check_link_status(intel_dp);
- drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+ if (!ctx)
+ drm_modeset_unlock(&dev->mode_config.connection_mutex);
goto out;
}
@@ -4682,18 +4687,19 @@ intel_dp_long_pulse(struct intel_connector *intel_connector)
return status;
}
-static enum drm_connector_status
-intel_dp_detect(struct drm_connector *connector, bool force)
+static int
+intel_dp_detect(struct drm_connector *connector,
+ struct drm_modeset_acquire_ctx *ctx)
{
struct intel_dp *intel_dp = intel_attached_dp(connector);
- enum drm_connector_status status = connector->status;
+ int status = connector->status;
DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
connector->base.id, connector->name);
/* If full detect is not performed yet, do a full detect */
if (!intel_dp->detect_done)
- status = intel_dp_long_pulse(intel_dp->attached_connector);
+ status = intel_dp_long_pulse(intel_dp->attached_connector, ctx);
intel_dp->detect_done = false;
@@ -5014,7 +5020,7 @@ void intel_dp_encoder_reset(struct drm_encoder *encoder)
static const struct drm_connector_funcs intel_dp_connector_funcs = {
.dpms = drm_atomic_helper_connector_dpms,
- .detect = intel_dp_detect,
+ .detect_ctx = intel_dp_detect,
.force = intel_dp_force,
.fill_modes = drm_helper_probe_single_connector_modes,
.set_property = intel_dp_set_property,
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index e24641b559e2..6ea8b9cd68c5 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1362,10 +1362,10 @@ int ironlake_get_lanes_required(int target_clock, int link_bw, int bpp);
void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
struct intel_digital_port *dport,
unsigned int expected_mask);
-bool intel_get_load_detect_pipe(struct drm_connector *connector,
- struct drm_display_mode *mode,
- struct intel_load_detect_pipe *old,
- struct drm_modeset_acquire_ctx *ctx);
+int intel_get_load_detect_pipe(struct drm_connector *connector,
+ struct drm_display_mode *mode,
+ struct intel_load_detect_pipe *old,
+ struct drm_modeset_acquire_ctx *ctx);
void intel_release_load_detect_pipe(struct drm_connector *connector,
struct intel_load_detect_pipe *old,
struct drm_modeset_acquire_ctx *ctx);
diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
index 7d210097eefa..d2d2af7ef305 100644
--- a/drivers/gpu/drm/i915/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/intel_hotplug.c
@@ -243,7 +243,11 @@ static bool intel_hpd_irq_event(struct drm_device *dev,
WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
old_status = connector->status;
- connector->status = connector->funcs->detect(connector, false);
+ if (connector->funcs->detect_ctx)
+ connector->status = connector->funcs->detect_ctx(connector, NULL);
+ else
+ connector->status = connector->funcs->detect(connector, false);
+
if (old_status == connector->status)
return false;
diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
index 6ed1a3ce47b7..d2c0120048b2 100644
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -1315,8 +1315,9 @@ static void intel_tv_find_better_format(struct drm_connector *connector)
* Currently this always returns CONNECTOR_STATUS_UNKNOWN, as we need to be sure
* we have a pipe programmed in order to probe the TV.
*/
-static enum drm_connector_status
-intel_tv_detect(struct drm_connector *connector, bool force)
+static int
+intel_tv_detect(struct drm_connector *connector,
+ struct drm_modeset_acquire_ctx *ctx)
{
struct drm_display_mode mode;
struct intel_tv *intel_tv = intel_attached_tv(connector);
@@ -1325,27 +1326,26 @@ intel_tv_detect(struct drm_connector *connector, bool force)
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force=%d\n",
connector->base.id, connector->name,
- force);
+ !!ctx);
mode = reported_modes[0];
- if (force) {
+ if (ctx) {
struct intel_load_detect_pipe tmp;
- struct drm_modeset_acquire_ctx ctx;
+ int ret;
- drm_modeset_acquire_init(&ctx, 0);
+ ret = intel_get_load_detect_pipe(connector, &mode, &tmp, ctx);
+ if (ret < 0)
+ return ret;
- if (intel_get_load_detect_pipe(connector, &mode, &tmp, &ctx)) {
+ if (ret > 0) {
type = intel_tv_detect_type(intel_tv, connector);
- intel_release_load_detect_pipe(connector, &tmp, &ctx);
+ intel_release_load_detect_pipe(connector, &tmp, ctx);
status = type < 0 ?
connector_status_disconnected :
connector_status_connected;
} else
status = connector_status_unknown;
-
- drm_modeset_drop_locks(&ctx);
- drm_modeset_acquire_fini(&ctx);
} else
return connector->status;
@@ -1516,7 +1516,7 @@ intel_tv_set_property(struct drm_connector *connector, struct drm_property *prop
static const struct drm_connector_funcs intel_tv_connector_funcs = {
.dpms = drm_atomic_helper_connector_dpms,
- .detect = intel_tv_detect,
+ .detect_ctx = intel_tv_detect,
.late_register = intel_connector_register,
.early_unregister = intel_connector_unregister,
.destroy = intel_tv_destroy,
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 941f57f311aa..834d1ba709ea 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -32,6 +32,7 @@
struct drm_device;
struct drm_connector_helper_funcs;
+struct drm_modeset_acquire_ctx;
struct drm_device;
struct drm_crtc;
struct drm_encoder;
@@ -385,6 +386,10 @@ struct drm_connector_funcs {
enum drm_connector_status (*detect)(struct drm_connector *connector,
bool force);
+ /* ctx = NULL <> detect(force = false), but may also return -EDEADLK. */
+ int (*detect_ctx)(struct drm_connector *connector,
+ struct drm_modeset_acquire_ctx *ctx);
+
/**
* @force:
*
--
2.7.4
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