Destructive load-detection is very expensive and due to failings elsewhere can trigger system wide stalls of up to 600ms. A simple first step to correcting this is not to invoke such an expensive and destructive load-detection operation automatically.

Whilst updating the other drivers, I did not find any as obviously broken as intel_crt_detect(), so I did not alter any of those detection routines except to update to reflect the new prototype.

v2: Julien Cristau pointed out that @nondestructive results in double-negatives and confusion when trying to interpret the parameter, so use @force instead. Much easier to type as well. ;-)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29536 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=16265 Reported-by: Bruno Prémont bonbons@linux-vserver.org Tested-by: Sitsofe Wheeler sitsofe@yahoo.com Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: stable@kernel.org --- drivers/gpu/drm/drm_crtc_helper.c | 4 ++-- drivers/gpu/drm/drm_sysfs.c | 2 +- drivers/gpu/drm/i915/intel_crt.c | 6 +++++- drivers/gpu/drm/i915/intel_dp.c | 2 +- drivers/gpu/drm/i915/intel_dvo.c | 3 ++- drivers/gpu/drm/i915/intel_hdmi.c | 2 +- drivers/gpu/drm/i915/intel_lvds.c | 7 +++++-- drivers/gpu/drm/i915/intel_sdvo.c | 5 +++-- drivers/gpu/drm/i915/intel_tv.c | 11 +++++------ drivers/gpu/drm/nouveau/nouveau_connector.c | 6 +++--- drivers/gpu/drm/radeon/radeon_connectors.c | 15 ++++++++++----- drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c | 3 ++- include/drm/drm_crtc.h | 10 +++++++++- 13 files changed, 49 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index e92ecda..a3e89eb 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -100,7 +100,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector, if (connector->funcs->force) connector->funcs->force(connector); } else - connector->status = connector->funcs->detect(connector); + connector->status = connector->funcs->detect(connector, true);

if (connector->status == connector_status_disconnected) { DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n", @@ -859,7 +859,7 @@ static void output_poll_execute(struct work_struct *work) !(connector->polled & DRM_CONNECTOR_POLL_HPD)) continue;

- status = connector->funcs->detect(connector); + status = connector->funcs->detect(connector, false); if (old_status != status) changed = true; } diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c index 86118a7..85da4c4 100644 --- a/drivers/gpu/drm/drm_sysfs.c +++ b/drivers/gpu/drm/drm_sysfs.c @@ -159,7 +159,7 @@ static ssize_t status_show(struct device *device, struct drm_connector *connector = to_drm_connector(device); enum drm_connector_status status;

- status = connector->funcs->detect(connector); + status = connector->funcs->detect(connector, true); return snprintf(buf, PAGE_SIZE, "%s\n", drm_get_connector_status_name(status)); } diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c index 4b77351..a02a8df 100644 --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -400,7 +400,8 @@ intel_crt_load_detect(struct drm_crtc *crtc, struct intel_encoder *intel_encoder return status; }

-static enum drm_connector_status intel_crt_detect(struct drm_connector *connector) +static enum drm_connector_status +intel_crt_detect(struct drm_connector *connector, bool force) { struct drm_device *dev = connector->dev; struct drm_encoder *encoder = intel_attached_encoder(connector); @@ -419,6 +420,9 @@ static enum drm_connector_status intel_crt_detect(struct drm_connector *connecto if (intel_crt_detect_ddc(encoder)) return connector_status_connected;

+ if (!force) + return connector->status; + /* for pre-945g platforms use load detect */ if (encoder->crtc && encoder->crtc->enabled) { status = intel_crt_load_detect(encoder->crtc, intel_encoder); diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 51d1429..1a51ee0 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1386,7 +1386,7 @@ ironlake_dp_detect(struct drm_connector *connector) * \return false if DP port is disconnected. */ static enum drm_connector_status -intel_dp_detect(struct drm_connector *connector) +intel_dp_detect(struct drm_connector *connector, bool force) { struct drm_encoder *encoder = intel_attached_encoder(connector); struct intel_dp *intel_dp = enc_to_intel_dp(encoder); diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c index a399f4b..7c9ec14 100644 --- a/drivers/gpu/drm/i915/intel_dvo.c +++ b/drivers/gpu/drm/i915/intel_dvo.c @@ -221,7 +221,8 @@ static void intel_dvo_mode_set(struct drm_encoder *encoder, * * Unimplemented. */ -static enum drm_connector_status intel_dvo_detect(struct drm_connector *connector) +static enum drm_connector_status +intel_dvo_detect(struct drm_connector *connector, bool force) { struct drm_encoder *encoder = intel_attached_encoder(connector); struct intel_dvo *intel_dvo = enc_to_intel_dvo(encoder); diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c index ccd4c97..926934a 100644 --- a/drivers/gpu/drm/i915/intel_hdmi.c +++ b/drivers/gpu/drm/i915/intel_hdmi.c @@ -139,7 +139,7 @@ static bool intel_hdmi_mode_fixup(struct drm_encoder *encoder, }

static enum drm_connector_status -intel_hdmi_detect(struct drm_connector *connector) +intel_hdmi_detect(struct drm_connector *connector, bool force) { struct drm_encoder *encoder = intel_attached_encoder(connector); struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder); diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c index 4fbb016..6ec39a8 100644 --- a/drivers/gpu/drm/i915/intel_lvds.c +++ b/drivers/gpu/drm/i915/intel_lvds.c @@ -445,7 +445,8 @@ static void intel_lvds_mode_set(struct drm_encoder *encoder, * connected and closed means disconnected. We also send hotplug events as * needed, using lid status notification from the input layer. */ -static enum drm_connector_status intel_lvds_detect(struct drm_connector *connector) +static enum drm_connector_status +intel_lvds_detect(struct drm_connector *connector, bool force) { struct drm_device *dev = connector->dev; enum drm_connector_status status = connector_status_connected; @@ -540,7 +541,9 @@ static int intel_lid_notify(struct notifier_block *nb, unsigned long val, * the LID nofication event. */ if (connector) - connector->status = connector->funcs->detect(connector); + connector->status = connector->funcs->detect(connector, + false); + /* Don't force modeset on machines where it causes a GPU lockup */ if (dmi_check_system(intel_no_modeset_on_lid)) return NOTIFY_OK; diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c index e3b7a7e..e8e902d 100644 --- a/drivers/gpu/drm/i915/intel_sdvo.c +++ b/drivers/gpu/drm/i915/intel_sdvo.c @@ -1417,7 +1417,7 @@ intel_analog_is_connected(struct drm_device *dev) if (!analog_connector) return false;

- if (analog_connector->funcs->detect(analog_connector) == + if (analog_connector->funcs->detect(analog_connector, false) == connector_status_disconnected) return false;

@@ -1486,7 +1486,8 @@ intel_sdvo_hdmi_sink_detect(struct drm_connector *connector) return status; }

-static enum drm_connector_status intel_sdvo_detect(struct drm_connector *connector) +static enum drm_connector_status +intel_sdvo_detect(struct drm_connector *connector, bool force) { uint16_t response; struct drm_encoder *encoder = intel_attached_encoder(connector); diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c index c671f60..4a117e3 100644 --- a/drivers/gpu/drm/i915/intel_tv.c +++ b/drivers/gpu/drm/i915/intel_tv.c @@ -1341,7 +1341,7 @@ static void intel_tv_find_better_format(struct drm_connector *connector) * we have a pipe programmed in order to probe the TV. */ static enum drm_connector_status -intel_tv_detect(struct drm_connector *connector) +intel_tv_detect(struct drm_connector *connector, bool force) { struct drm_display_mode mode; struct drm_encoder *encoder = intel_attached_encoder(connector); @@ -1353,7 +1353,7 @@ intel_tv_detect(struct drm_connector *connector)

if (encoder->crtc && encoder->crtc->enabled) { type = intel_tv_detect_type(intel_tv); - } else { + } else if (force) { struct drm_crtc *crtc; int dpms_mode;

@@ -1364,10 +1364,9 @@ intel_tv_detect(struct drm_connector *connector) intel_release_load_detect_pipe(&intel_tv->base, connector, dpms_mode); } else - type = -1; - } - - intel_tv->type = type; + return connector_status_unknown; + } else + return connector->status;

if (type < 0) return connector_status_disconnected; diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c index a1473ff..87186a4 100644 --- a/drivers/gpu/drm/nouveau/nouveau_connector.c +++ b/drivers/gpu/drm/nouveau/nouveau_connector.c @@ -168,7 +168,7 @@ nouveau_connector_set_encoder(struct drm_connector *connector, }

static enum drm_connector_status -nouveau_connector_detect(struct drm_connector *connector) +nouveau_connector_detect(struct drm_connector *connector, bool force) { struct drm_device *dev = connector->dev; struct nouveau_connector *nv_connector = nouveau_connector(connector); @@ -246,7 +246,7 @@ detect_analog: }

static enum drm_connector_status -nouveau_connector_detect_lvds(struct drm_connector *connector) +nouveau_connector_detect_lvds(struct drm_connector *connector, bool force) { struct drm_device *dev = connector->dev; struct drm_nouveau_private *dev_priv = dev->dev_private; @@ -267,7 +267,7 @@ nouveau_connector_detect_lvds(struct drm_connector *connector)

/* Try retrieving EDID via DDC */ if (!dev_priv->vbios.fp_no_ddc) { - status = nouveau_connector_detect(connector); + status = nouveau_connector_detect(connector, force); if (status == connector_status_connected) goto out; } diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c index 1a5ee39..f84e8d3 100644 --- a/drivers/gpu/drm/radeon/radeon_connectors.c +++ b/drivers/gpu/drm/radeon/radeon_connectors.c @@ -481,7 +481,8 @@ static int radeon_lvds_mode_valid(struct drm_connector *connector, return MODE_OK; }

-static enum drm_connector_status radeon_lvds_detect(struct drm_connector *connector) +static enum drm_connector_status +radeon_lvds_detect(struct drm_connector *connector, bool force) { struct radeon_connector *radeon_connector = to_radeon_connector(connector); struct drm_encoder *encoder = radeon_best_single_encoder(connector); @@ -594,7 +595,8 @@ static int radeon_vga_mode_valid(struct drm_connector *connector, return MODE_OK; }

-static enum drm_connector_status radeon_vga_detect(struct drm_connector *connector) +static enum drm_connector_status +radeon_vga_detect(struct drm_connector *connector, bool force) { struct radeon_connector *radeon_connector = to_radeon_connector(connector); struct drm_encoder *encoder; @@ -691,7 +693,8 @@ static int radeon_tv_mode_valid(struct drm_connector *connector, return MODE_OK; }

-static enum drm_connector_status radeon_tv_detect(struct drm_connector *connector) +static enum drm_connector_status +radeon_tv_detect(struct drm_connector *connector, bool force) { struct drm_encoder *encoder; struct drm_encoder_helper_funcs *encoder_funcs; @@ -748,7 +751,8 @@ static int radeon_dvi_get_modes(struct drm_connector *connector) * we have to check if this analog encoder is shared with anyone else (TV) * if its shared we have to set the other connector to disconnected. */ -static enum drm_connector_status radeon_dvi_detect(struct drm_connector *connector) +static enum drm_connector_status +radeon_dvi_detect(struct drm_connector *connector, bool force) { struct radeon_connector *radeon_connector = to_radeon_connector(connector); struct drm_encoder *encoder = NULL; @@ -972,7 +976,8 @@ static int radeon_dp_get_modes(struct drm_connector *connector) return ret; }

-static enum drm_connector_status radeon_dp_detect(struct drm_connector *connector) +static enum drm_connector_status +radeon_dp_detect(struct drm_connector *connector, bool force) { struct radeon_connector *radeon_connector = to_radeon_connector(connector); enum drm_connector_status ret = connector_status_disconnected; diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c index 2ff5cf7..2e7e258 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c @@ -335,7 +335,8 @@ static void vmw_ldu_connector_restore(struct drm_connector *connector) }

static enum drm_connector_status - vmw_ldu_connector_detect(struct drm_connector *connector) + vmw_ldu_connector_detect(struct drm_connector *connector, + bool force) { if (vmw_connector_to_ldu(connector)->pref_active) return connector_status_connected; diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index c9f3cc5..3e5a51a 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -386,7 +386,15 @@ struct drm_connector_funcs { void (*dpms)(struct drm_connector *connector, int mode); void (*save)(struct drm_connector *connector); void (*restore)(struct drm_connector *connector); - enum drm_connector_status (*detect)(struct drm_connector *connector); + + /* Check to see if anything is attached to the connector. + * @force is set to false whilst polling, true when checking the + * connector due to user request. @force can be used by the driver + * to avoid expensive, destructive operations during automated + * probing. + */ + enum drm_connector_status (*detect)(struct drm_connector *connector, + bool force); int (*fill_modes)(struct drm_connector *connector, uint32_t max_width, uint32_t max_height); int (*set_property)(struct drm_connector *connector, struct drm_property *property, uint64_t val);