From 542ba979b4fa1e07ff2ad2dabbdc12e92b80ed46 Mon Sep 17 00:00:00 2001 From: Tim Gover Date: Thu, 13 Jul 2023 17:47:22 +0100 Subject: [PATCH] drm/vc4: Enable SCALER_CONTROL early in HVS init Always enable SCALER_CONTROL before attempting other HVS operations. It's safe to write to some parts of the HVS but in general it's dangerous to do this because it can cause bus lockups. Signed-off-by: Tim Gover --- drivers/gpu/drm/vc4/vc4_hvs.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/drivers/gpu/drm/vc4/vc4_hvs.c +++ b/drivers/gpu/drm/vc4/vc4_hvs.c @@ -1303,6 +1303,10 @@ static int vc4_hvs_hw_init(struct vc4_hv struct vc4_dev *vc4 = hvs->vc4; u32 dispctrl, reg; + dispctrl = HVS_READ(SCALER_DISPCTRL); + dispctrl |= SCALER_DISPCTRL_ENABLE; + HVS_WRITE(SCALER_DISPCTRL, dispctrl); + reg = HVS_READ(SCALER_DISPECTRL); reg &= ~SCALER_DISPECTRL_DSP2_MUX_MASK; HVS_WRITE(SCALER_DISPECTRL, @@ -1324,8 +1328,6 @@ static int vc4_hvs_hw_init(struct vc4_hv reg | VC4_SET_FIELD(3, SCALER_DISPDITHER_DSP5_MUX)); dispctrl = HVS_READ(SCALER_DISPCTRL); - - dispctrl |= SCALER_DISPCTRL_ENABLE; dispctrl |= SCALER_DISPCTRL_DISPEIRQ(0) | SCALER_DISPCTRL_DISPEIRQ(1) | SCALER_DISPCTRL_DISPEIRQ(2); @@ -1521,6 +1523,10 @@ static int vc4_hvs_bind(struct device *d else hvs->dlist = hvs->regs + SCALER5_DLIST_START; + ret = vc4_hvs_hw_init(hvs); + if (ret) + return ret; + /* Upload filter kernels. We only have the one for now, so we * keep it around for the lifetime of the driver. */ @@ -1530,10 +1536,6 @@ static int vc4_hvs_bind(struct device *d if (ret) return ret; - ret = vc4_hvs_hw_init(hvs); - if (ret) - return ret; - ret = vc4_hvs_cob_init(hvs); if (ret) return ret;