drm/vc4: hvs: Correct logic on stopping an HVS channel

When factoring out __vc4_hvs_stop_channel, the logic got inverted from
	if (condition)
	  // stop channel
to
	if (condition)
	  goto out
	//stop channel
	out:
and also changed the exact register writes used to stop the channel.

Correct the logic so that the channel is actually stopped, and revert
to the original register writes.

Fixes: 6d01a106b4c8 ("drm/vc4: crtc: Move HVS init and close to a function")
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240621152055.4180873-32-dave.stevenson@raspberrypi.com
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index 93e7edd8b084b32e7738a79ae5ba335dabbc7735..2a366a607fcc1d832addfacfae304377330d4ccd 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -427,13 +427,11 @@ void vc4_hvs_stop_channel(struct vc4_hvs *hvs, unsigned int chan)
        if (!drm_dev_enter(drm, &idx))
                return;
 
-       if (HVS_READ(SCALER_DISPCTRLX(chan)) & SCALER_DISPCTRLX_ENABLE)
+       if (!(HVS_READ(SCALER_DISPCTRLX(chan)) & SCALER_DISPCTRLX_ENABLE))
                goto out;
 
-       HVS_WRITE(SCALER_DISPCTRLX(chan),
-                 HVS_READ(SCALER_DISPCTRLX(chan)) | SCALER_DISPCTRLX_RESET);
-       HVS_WRITE(SCALER_DISPCTRLX(chan),
-                 HVS_READ(SCALER_DISPCTRLX(chan)) & ~SCALER_DISPCTRLX_ENABLE);
+       HVS_WRITE(SCALER_DISPCTRLX(chan), SCALER_DISPCTRLX_RESET);
+       HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
 
        /* Once we leave, the scaler should be disabled and its fifo empty. */
        WARN_ON_ONCE(HVS_READ(SCALER_DISPCTRLX(chan)) & SCALER_DISPCTRLX_RESET);