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| author | zain wang <wzz@rock-chips.com> | 2018-04-23 12:49:41 +0200 |
|---|---|---|
| committer | Andrzej Hajda <a.hajda@samsung.com> | 2018-04-24 08:34:33 +0200 |
| commit | 7f6414143a61f9eb369c90ef0550c9ef8e603d57 (patch) | |
| tree | 8b54d5660b6ba88d1e2916ce2e2146dfaba6afc3 /drivers/gpu/drm | |
| parent | 8a335736f94edc9c8c977d931301e6a0326fbc3e (diff) | |
| download | op-kernel-dev-7f6414143a61f9eb369c90ef0550c9ef8e603d57.zip op-kernel-dev-7f6414143a61f9eb369c90ef0550c9ef8e603d57.tar.gz | |
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 <marcheu@chromium.org>
Signed-off-by: zain wang <wzz@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180423105003.9004-6-enric.balletbo@collabora.com
Diffstat (limited to 'drivers/gpu/drm')
| -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 bf805f1..3269dee 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; |
