Re: [PATCH v3 055/105] drm/vc4: hvs: Introduce a function to get the assigned FIFO

On Wed, May 27, 2020 at 8:50 AM Maxime Ripard maxime@cerno.tech wrote:

At boot time, if we detect that a pixelvalve has been enabled, we need to be able to retrieve the HVS channel it has been assigned to so that we can disable that channel too. Let's create that function that returns the FIFO or an error from a given output.

Signed-off-by: Maxime Ripard maxime@cerno.tech

+int vc4_hvs_get_fifo_from_output(struct drm_device *dev, unsigned int output) +{

•   struct vc4_dev *vc4 = to_vc4_dev(dev);
  

•   u32 reg;
  

•   int ret;
  

•   switch (output) {
  

•   case 0:
  

•           return 0;
  

•   case 1:
  

•           return 1;
  

•   case 2:
  

•           reg = HVS_READ(SCALER_DISPECTRL);
  

•           ret = FIELD_GET(SCALER_DISPECTRL_DSP2_MUX_MASK, reg);
  

•           if (ret == 0)
  

•                   return 2;
  

•           return 0;
  

•   case 3:
  

•           reg = HVS_READ(SCALER_DISPCTRL);
  

•           ret = FIELD_GET(SCALER_DISPCTRL_DSP3_MUX_MASK, reg);
  

•           if (ret == 3)
  

•                   return -EPIPE;
  

•           return ret;
  

•   case 4:
  

•           reg = HVS_READ(SCALER_DISPEOLN);
  

•           ret = FIELD_GET(SCALER_DISPEOLN_DSP4_MUX_MASK, reg);
  

•           if (ret == 3)
  

•                   return -EPIPE;
  

•           return ret;
  

•   case 5:
  

•           reg = HVS_READ(SCALER_DISPDITHER);
  

•           ret = FIELD_GET(SCALER_DISPDITHER_DSP5_MUX_MASK, reg);
  

•           if (ret == 3)
  

•                   return -EPIPE;
  

Oh, FIELD_GET is new to me. Looks like we should replace VC4_GET_FIELD usage with just using that header, and also VC4_SET_FIELD with WARN_ON(!FIELD_FIT()); FIELD_PREP.

Could you follow up with that? Other than that, 54-67 r-b.