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authorJesse Barnes <jbarnes@virtuousgeek.org>2011-07-07 11:11:00 -0700
committerKeith Packard <keithp@keithp.com>2011-07-07 13:38:44 -0700
commit899526d9a73fda47516cf11ccb3467ad6702f568 (patch)
treed4bdec27956e40aaa9209da438cea6ae3ef8f7f0 /drivers/gpu
parent59cd09e1aea3ac6eb15b45e5d2261a63ecb1799c (diff)
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drm/i915/dp: try to read receiver capabilities 3 times when detecting
If ->detect is called too soon after a hot plug event, the sink may not be ready yet. So try up to 3 times with 1ms sleeps in between tries to get the data (spec dictates that receivers must be ready to respond within 1ms and that sources should try 3 times). See section 9.1 of the 1.1a DisplayPort spec. Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Reviewed-by: Keith Packard <keithp@keithp.com> Signed-off-by: Keith Packard <keithp@keithp.com>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/i915/intel_dp.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index a9a5051419df..70075d9900da 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1551,6 +1551,7 @@ static enum drm_connector_status
ironlake_dp_detect(struct intel_dp *intel_dp)
{
enum drm_connector_status status;
+ int ret, i;
/* Can't disconnect eDP, but you can close the lid... */
if (is_edp(intel_dp)) {
@@ -1561,12 +1562,16 @@ ironlake_dp_detect(struct intel_dp *intel_dp)
}
status = connector_status_disconnected;
- if (intel_dp_aux_native_read(intel_dp,
- 0x000, intel_dp->dpcd,
- sizeof (intel_dp->dpcd))
- == sizeof(intel_dp->dpcd)) {
- if (intel_dp->dpcd[DP_DPCD_REV] != 0)
+ for (i = 0; i < 3; i++) {
+ ret = intel_dp_aux_native_read(intel_dp,
+ 0x000, intel_dp->dpcd,
+ sizeof (intel_dp->dpcd));
+ if (ret == sizeof(intel_dp->dpcd) &&
+ intel_dp->dpcd[DP_DPCD_REV] != 0) {
status = connector_status_connected;
+ break;
+ }
+ msleep(1);
}
DRM_DEBUG_KMS("DPCD: %hx%hx%hx%hx\n", intel_dp->dpcd[0],
intel_dp->dpcd[1], intel_dp->dpcd[2], intel_dp->dpcd[3]);