From 11fe1266253a96c4d4ac9c07918372a98248c62e Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Fri, 16 Mar 2012 12:22:11 -0400 Subject: [PATCH] drm/radeon/kms: reduce probe latency on digital connectors On a system with one HDMI and one VGA connector the latter causes output polling to run every ten seconds. This causes full EDID re-fetch on every poll and approx. 100ms rendering stalls are experienced by full screen page-flipping applications. Optimisation is to trust HPD sense on R600+ ASICs and to skip doing these expensive probes unless HPD sense has changed. Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=47007 agd5f: fix patch and message formatting. Signed-off-by: Tvrtko Ursulin Signed-off-by: Alex Deucher Signed-off-by: Dave Airlie --- drivers/gpu/drm/radeon/radeon_connectors.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c index d2e6144..64774ac 100644 --- a/drivers/gpu/drm/radeon/radeon_connectors.c +++ b/drivers/gpu/drm/radeon/radeon_connectors.c @@ -827,6 +827,27 @@ static int radeon_dvi_get_modes(struct drm_connector *connector) return ret; } +static bool radeon_check_hpd_status_unchanged(struct drm_connector *connector) +{ + struct drm_device *dev = connector->dev; + struct radeon_device *rdev = dev->dev_private; + struct radeon_connector *radeon_connector = to_radeon_connector(connector); + enum drm_connector_status status; + + /* We only trust HPD on R600 and newer ASICS. */ + if (rdev->family >= CHIP_R600 + && radeon_connector->hpd.hpd != RADEON_HPD_NONE) { + if (radeon_hpd_sense(rdev, radeon_connector->hpd.hpd)) + status = connector_status_connected; + else + status = connector_status_disconnected; + if (connector->status == status) + return true; + } + + return false; +} + /* * DVI is complicated * Do a DDC probe, if DDC probe passes, get the full EDID so @@ -851,6 +872,9 @@ radeon_dvi_detect(struct drm_connector *connector, bool force) enum drm_connector_status ret = connector_status_disconnected; bool dret = false; + if (!force && radeon_check_hpd_status_unchanged(connector)) + return connector->status; + if (radeon_connector->ddc_bus) dret = radeon_ddc_probe(radeon_connector); if (dret) { @@ -1254,6 +1278,9 @@ radeon_dp_detect(struct drm_connector *connector, bool force) struct radeon_connector_atom_dig *radeon_dig_connector = radeon_connector->con_priv; struct drm_encoder *encoder = radeon_best_single_encoder(connector); + if (!force && radeon_check_hpd_status_unchanged(connector)) + return connector->status; + if (radeon_connector->edid) { kfree(radeon_connector->edid); radeon_connector->edid = NULL; -- 2.7.4