drm/vc4: hvs: Set AXI panic modes for the HVS

[ Upstream commit 014eccc9da7bfc76a3107fceea37dd60f1d63630 ]

The HVS can change AXI request mode based on how full the COB
FIFOs are.
Until now the vc4 driver has been relying on the firmware to
have set these to sensible values.

With HVS channel 2 now being used for live video, change the
panic mode for all channels to be explicitly set by the driver,
and the same for all channels.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240621152055.4180873-7-dave.stevenson@raspberrypi.com
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index f8f2fc3d15f73ddf25246032ff292b12236d9d11..64a02e29b7cb171f24d4bef6cb898f521b7190d3 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -688,6 +688,17 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
        dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_PANIC1);
        dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_PANIC2);
 
+       /* Set AXI panic mode.
+        * VC4 panics when < 2 lines in FIFO.
+        * VC5 panics when less than 1 line in the FIFO.
+        */
+       dispctrl &= ~(SCALER_DISPCTRL_PANIC0_MASK |
+                     SCALER_DISPCTRL_PANIC1_MASK |
+                     SCALER_DISPCTRL_PANIC2_MASK);
+       dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_PANIC0);
+       dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_PANIC1);
+       dispctrl |= VC4_SET_FIELD(2, SCALER_DISPCTRL_PANIC2);
+
        HVS_WRITE(SCALER_DISPCTRL, dispctrl);
 
        ret = devm_request_irq(dev, platform_get_irq(pdev, 0),