drm/vc4: txp: Don't set TXP_VSTART_AT_EOF

[ Upstream commit 234998df929f14d00cbf2f1e81a7facb69fd9266 ]

The TXP_VSTART_AT_EOF will generate a second VSTART signal to the HVS.
However, the HVS waits for VSTART to enable the FIFO and will thus start
filling the FIFO before the start of the frame.

This leads to corruption at the beginning of the first frame, and
content from the previous frame at the beginning of the next frames.

Since one VSTART is enough, let's get rid of it.

Fixes: 008095e065a8 ("drm/vc4: Add support for the transposer block")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20220328153659.2382206-3-maxime@cerno.tech
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c
index 6e23c50168f9ab2bb6574d44b3790e501959ce50..9b7810c3dd659a4a77b0bf0f324a8e4aa8d3d685 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_txp.c
+++ b/drivers/gpu/drm/vc4/vc4_txp.c
@@ -311,7 +311,7 @@ static void vc4_txp_connector_atomic_commit(struct drm_connector *conn,
        if (WARN_ON(i == ARRAY_SIZE(drm_fmts)))
                return;
 
-       ctrl = TXP_GO | TXP_VSTART_AT_EOF | TXP_EI |
+       ctrl = TXP_GO | TXP_EI |
               VC4_SET_FIELD(0xf, TXP_BYTE_ENABLE) |
               VC4_SET_FIELD(txp_fmts[i], TXP_FORMAT);