diff options
| author | Jesse Barnes <jbarnes@virtuousgeek.org> | 2011-07-07 11:11:00 -0700 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2011-07-07 13:38:44 -0700 |
| commit | 899526d9a73fda47516cf11ccb3467ad6702f568 (patch) | |
| tree | d4bdec27956e40aaa9209da438cea6ae3ef8f7f0 /drivers | |
| parent | 59cd09e1aea3ac6eb15b45e5d2261a63ecb1799c (diff) | |
| download | linux-899526d9a73fda47516cf11ccb3467ad6702f568.tar.gz linux-899526d9a73fda47516cf11ccb3467ad6702f568.tar.bz2 linux-899526d9a73fda47516cf11ccb3467ad6702f568.zip | |
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')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 15 |
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]); |