target/linux/bcm27xx/patches-6.1/950-0955-drm-vc4-Enable-SCALER_CONTROL-early-in-HVS-init.patch

   1 From 542ba979b4fa1e07ff2ad2dabbdc12e92b80ed46 Mon Sep 17 00:00:00 2001
   2 From: Tim Gover <tim.gover@raspberrypi.com>
   3 Date: Thu, 13 Jul 2023 17:47:22 +0100
   4 Subject: [PATCH] drm/vc4: Enable SCALER_CONTROL early in HVS init
   5
   6 Always enable SCALER_CONTROL before attempting other HVS
   7 operations. It's safe to write to some parts of the HVS but
   8 in general it's dangerous to do this because it can cause bus
   9 lockups.
  10
  11 Signed-off-by: Tim Gover <tim.gover@raspberrypi.com>
  12 ---
  13  drivers/gpu/drm/vc4/vc4_hvs.c | 14 ++++++++------
  14  1 file changed, 8 insertions(+), 6 deletions(-)
  15
  16 --- a/drivers/gpu/drm/vc4/vc4_hvs.c
  17 +++ b/drivers/gpu/drm/vc4/vc4_hvs.c
  18 @@ -1303,6 +1303,10 @@ static int vc4_hvs_hw_init(struct vc4_hv
  19         struct vc4_dev *vc4 = hvs->vc4;
  20         u32 dispctrl, reg;
  21
  22 +       dispctrl = HVS_READ(SCALER_DISPCTRL);
  23 +       dispctrl |= SCALER_DISPCTRL_ENABLE;
  24 +       HVS_WRITE(SCALER_DISPCTRL, dispctrl);
  25 +
  26         reg = HVS_READ(SCALER_DISPECTRL);
  27         reg &= ~SCALER_DISPECTRL_DSP2_MUX_MASK;
  28         HVS_WRITE(SCALER_DISPECTRL,
  29 @@ -1324,8 +1328,6 @@ static int vc4_hvs_hw_init(struct vc4_hv
  30                   reg | VC4_SET_FIELD(3, SCALER_DISPDITHER_DSP5_MUX));
  31
  32         dispctrl = HVS_READ(SCALER_DISPCTRL);
  33 -
  34 -       dispctrl |= SCALER_DISPCTRL_ENABLE;
  35         dispctrl |= SCALER_DISPCTRL_DISPEIRQ(0) |
  36                     SCALER_DISPCTRL_DISPEIRQ(1) |
  37                     SCALER_DISPCTRL_DISPEIRQ(2);
  38 @@ -1521,6 +1523,10 @@ static int vc4_hvs_bind(struct device *d
  39         else
  40                 hvs->dlist = hvs->regs + SCALER5_DLIST_START;
  41
  42 +       ret = vc4_hvs_hw_init(hvs);
  43 +       if (ret)
  44 +               return ret;
  45 +
  46         /* Upload filter kernels.  We only have the one for now, so we
  47          * keep it around for the lifetime of the driver.
  48          */
  49 @@ -1530,10 +1536,6 @@ static int vc4_hvs_bind(struct device *d
  50         if (ret)
  51                 return ret;
  52
  53 -       ret = vc4_hvs_hw_init(hvs);
  54 -       if (ret)
  55 -               return ret;
  56 -
  57         ret = vc4_hvs_cob_init(hvs);
  58         if (ret)
  59                 return ret;