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| author | Neil Armstrong <narmstrong@baylibre.com> | 2022-02-04 17:33:37 +0300 |
|---|---|---|
| committer | Neil Armstrong <narmstrong@baylibre.com> | 2022-02-10 18:36:53 +0300 |
| commit | 1528038385c0a706aac9ac165eeb24044fef6825 (patch) | |
| tree | 02b056101904d3573e801e48eb7f80430d7de280 /drivers/gpu/drm/bridge/synopsys | |
| parent | ded74cafeea9311c1eaf6fccce963de2516145f7 (diff) | |
| download | linux-1528038385c0a706aac9ac165eeb24044fef6825.tar.xz | |
drm/bridge: dw-hdmi: use safe format when first in bridge chain
When the dw-hdmi bridge is in first place of the bridge chain, this
means there is no way to select an input format of the dw-hdmi HW
component.
Since introduction of display-connector, negotiation was broken since
the dw-hdmi negotiation code only worked when the dw-hdmi bridge was
in last position of the bridge chain or behind another bridge also
supporting input & output format negotiation.
Commit 7cd70656d128 ("drm/bridge: display-connector: implement bus fmts callbacks")
was introduced to make negotiation work again by making display-connector
act as a pass-through concerning input & output format negotiation.
But in the case where the dw-hdmi is single in the bridge chain, for
example on Renesas SoCs, with the display-connector bridge the dw-hdmi
is no more single, breaking output format.
Reported-by: Biju Das <biju.das.jz@bp.renesas.com>
Bisected-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Fixes: 6c3c719936da ("drm/bridge: synopsys: dw-hdmi: add bus format negociation")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
[narmstrong: add proper fixes commit]
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204143337.89221-1-narmstrong@baylibre.com
Diffstat (limited to 'drivers/gpu/drm/bridge/synopsys')
| -rw-r--r-- | drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index b0d8110dd412..4befc104d220 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -2551,8 +2551,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, if (!output_fmts) return NULL; - /* If dw-hdmi is the only bridge, avoid negociating with ourselves */ - if (list_is_singular(&bridge->encoder->bridge_chain)) { + /* If dw-hdmi is the first or only bridge, avoid negociating with ourselves */ + if (list_is_singular(&bridge->encoder->bridge_chain) || + list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) { *num_output_fmts = 1; output_fmts[0] = MEDIA_BUS_FMT_FIXED; |