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 3856ac289d38081517926d6b740afe2c52446dcd..69b2936a5f4ad7b1e4d39a55c56ea36498a77bb0 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -729,6 +729,17 @@ 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),