diff options
| author | zain wang <[email protected]> | 2018-04-23 12:49:41 +0200 |
|---|---|---|
| committer | Andrzej Hajda <[email protected]> | 2018-04-24 08:34:33 +0200 |
| commit | 7f6414143a61f9eb369c90ef0550c9ef8e603d57 (patch) | |
| tree | 8b54d5660b6ba88d1e2916ce2e2146dfaba6afc3 | |
| parent | 8a335736f94edc9c8c977d931301e6a0326fbc3e (diff) | |
drm/bridge: analogix_dp: Wait for HPD signal before configuring link
According to DP spec v1.3 chap 3.5.1.2 Link Training, Link Policy Maker
must first detect that the HPD signal is asserted high by the Downstream
Device before establishing a link with it.
Cc: Stéphane Marchesin <[email protected]>
Signed-off-by: zain wang <[email protected]>
Signed-off-by: Sean Paul <[email protected]>
Signed-off-by: Thierry Escande <[email protected]>
Signed-off-by: Enric Balletbo i Serra <[email protected]>
Tested-by: Marek Szyprowski <[email protected]>
Reviewed-by: Archit Taneja <[email protected]>
Signed-off-by: Andrzej Hajda <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
| -rw-r--r-- | drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index bf805f156272..3269deec739d 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1169,6 +1169,17 @@ static int analogix_dp_set_bridge(struct analogix_dp_device *dp) if (ret) goto out_dp_init; + /* + * According to DP spec v1.3 chap 3.5.1.2 Link Training, + * We should first make sure the HPD signal is asserted high by device + * when we want to establish a link with it. + */ + ret = analogix_dp_detect_hpd(dp); + if (ret) { + DRM_ERROR("failed to get hpd single ret = %d\n", ret); + goto out_dp_init; + } + ret = analogix_dp_commit(dp); if (ret) goto out_dp_init; |