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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 <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
hifive-unleashed-5.1
Tvrtko Ursulin 2012-03-16 12:22:11 -04:00 committed by Dave Airlie
parent 4c1b2d2da3
commit 11fe126625
1 changed files with 27 additions and 0 deletions
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27
drivers/gpu/drm/radeon/radeon_connectors.c
View File

@ -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;