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drm: bridge: ti-sn65dsi83: Remove NO_HFP and NO_HBP mode flags for LVDS stability

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The current DSI mode configuration disables horizontal front porch
(HFP) and back porch (HBP) transmission using
MIPI_DSI_MODE_VIDEO_NO_HFP and MIPI_DSI_MODE_VIDEO_NO_HBP.

However, the SN65DSI83/84 bridge relies on receiving full horizontal
timing information over DSI in order to correctly reconstruct the
LVDS output timings. When HFP and HBP are not transmitted, the bridge
cannot recreate the required timing parameters, resulting in unstable
or missing display output on some panels.

The SN65DSI84 datasheet also describes transmission of complete
horizontal timing information as part of the DSI video stream.

Remove MIPI_DSI_MODE_VIDEO_NO_HFP and MIPI_DSI_MODE_VIDEO_NO_HBP
so that HFP and HBP timing information is transmitted to the bridge.

Reference:
SN65DSI84 Datasheet, Section 7.4.7 (page 20):
https://www.ti.com/lit/ds/symlink/sn65dsi84.pdf

Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Sudarshan Shetty <tessolveupstream@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://patch.msgid.link/20260527085736.920390-2-tessolveupstream@gmail.com
[Luca: cleaned up datasheet URL]
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
This commit is contained in:
Sudarshan Shetty
2026-05-27 14:27:35 +05:30
committed by Luca Ceresoli
parent ef1d150697
commit 4af021a977
1 changed files with 0 additions and 1 deletions
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1
drivers/gpu/drm/bridge/ti-sn65dsi83.c
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@@ -977,7 +977,6 @@ static int sn65dsi83_host_attach(struct sn65dsi83 *ctx)
dsi->lanes = dsi_lanes;
dsi->format = MIPI_DSI_FMT_RGB888;
dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
MIPI_DSI_MODE_VIDEO_NO_HFP | MIPI_DSI_MODE_VIDEO_NO_HBP |
MIPI_DSI_MODE_VIDEO_NO_HSA | MIPI_DSI_MODE_NO_EOT_PACKET;
ret = devm_mipi_dsi_attach(dev, dsi);