[Intel-gfx] [RESEND] drm/i915/display: stop using BUG()

[Ville Syrjälä]

On Tue, May 31, 2022 at 07:25:27PM +0300, Jani Nikula wrote:
> Avoid bringing the entire machine down even if there's a bug that
> shouldn't happen, but won't corrupt the system either. Log them loudly
> and limp on.
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c      | 11 ++++++-----
>  drivers/gpu/drm/i915/display/intel_display.c  | 19 +++++++++++--------
>  .../drm/i915/display/intel_display_types.h    | 15 +++++++++------
>  3 files changed, 26 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 333871cf3a2c..915e8e3e8f38 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -455,6 +455,9 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder,
>  		temp |= TRANS_DDI_SELECT_PORT(port);
>  
>  	switch (crtc_state->pipe_bpp) {
> +	default:
> +		MISSING_CASE(crtc_state->pipe_bpp);
> +		fallthrough;
>  	case 18:
>  		temp |= TRANS_DDI_BPC_6;
>  		break;
> @@ -467,8 +470,6 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder,
>  	case 36:
>  		temp |= TRANS_DDI_BPC_12;
>  		break;
> -	default:
> -		BUG();
>  	}
>  
>  	if (crtc_state->hw.adjusted_mode.flags & DRM_MODE_FLAG_PVSYNC)
> @@ -478,6 +479,9 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder,
>  
>  	if (cpu_transcoder == TRANSCODER_EDP) {
>  		switch (pipe) {
> +		default:
> +			MISSING_CASE(pipe);
> +			fallthrough;
>  		case PIPE_A:
>  			/* On Haswell, can only use the always-on power well for
>  			 * eDP when not using the panel fitter, and when not
> @@ -494,9 +498,6 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder,
>  		case PIPE_C:
>  			temp |= TRANS_DDI_EDP_INPUT_C_ONOFF;
>  			break;
> -		default:
> -			BUG();
> -			break;
>  		}
>  	}
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 806d50b302ab..e6a84d97718f 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -500,6 +500,9 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
>  	i915_reg_t dpll_reg;
>  
>  	switch (dig_port->base.port) {
> +	default:
> +		MISSING_CASE(dig_port->base.port);
> +		fallthrough;
>  	case PORT_B:
>  		port_mask = DPLL_PORTB_READY_MASK;
>  		dpll_reg = DPLL(0);
> @@ -513,8 +516,6 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
>  		port_mask = DPLL_PORTD_READY_MASK;
>  		dpll_reg = DPIO_PHY_STATUS;
>  		break;
> -	default:
> -		BUG();
>  	}
>  
>  	if (intel_de_wait_for_register(dev_priv, dpll_reg,
> @@ -3157,6 +3158,10 @@ static void i9xx_set_pipeconf(const struct intel_crtc_state *crtc_state)
>  				    PIPECONF_DITHER_TYPE_SP;
>  
>  		switch (crtc_state->pipe_bpp) {
> +		default:
> +			/* Case prevented by intel_choose_pipe_bpp_dither. */
> +			MISSING_CASE(crtc_state->pipe_bpp);
> +			fallthrough;
>  		case 18:
>  			pipeconf |= PIPECONF_BPC_6;
>  			break;
> @@ -3166,9 +3171,6 @@ static void i9xx_set_pipeconf(const struct intel_crtc_state *crtc_state)
>  		case 30:
>  			pipeconf |= PIPECONF_BPC_10;
>  			break;
> -		default:
> -			/* Case prevented by intel_choose_pipe_bpp_dither. */
> -			BUG();
>  		}
>  	}
>  
> @@ -3464,6 +3466,10 @@ static void ilk_set_pipeconf(const struct intel_crtc_state *crtc_state)
>  	val = 0;
>  
>  	switch (crtc_state->pipe_bpp) {
> +	default:
> +		/* Case prevented by intel_choose_pipe_bpp_dither. */
> +		MISSING_CASE(crtc_state->pipe_bpp);
> +		fallthrough;
>  	case 18:
>  		val |= PIPECONF_BPC_6;
>  		break;
> @@ -3476,9 +3482,6 @@ static void ilk_set_pipeconf(const struct intel_crtc_state *crtc_state)
>  	case 36:
>  		val |= PIPECONF_BPC_12;
>  		break;
> -	default:
> -		/* Case prevented by intel_choose_pipe_bpp_dither. */
> -		BUG();
>  	}
>  
>  	if (crtc_state->dither)
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index a27d66fd4383..37c25364350c 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1798,13 +1798,14 @@ static inline enum dpio_channel
>  vlv_dig_port_to_channel(struct intel_digital_port *dig_port)
>  {
>  	switch (dig_port->base.port) {
> +	default:
> +		MISSING_CASE(dig_port->base.port);
> +		fallthrough;
>  	case PORT_B:
>  	case PORT_D:
>  		return DPIO_CH0;
>  	case PORT_C:
>  		return DPIO_CH1;
> -	default:
> -		BUG();
>  	}
>  }
>  
> @@ -1812,13 +1813,14 @@ static inline enum dpio_phy
>  vlv_dig_port_to_phy(struct intel_digital_port *dig_port)
>  {
>  	switch (dig_port->base.port) {
> +	default:
> +		MISSING_CASE(dig_port->base.port);
> +		fallthrough;
>  	case PORT_B:
>  	case PORT_C:
>  		return DPIO_PHY0;
>  	case PORT_D:
>  		return DPIO_PHY1;
> -	default:
> -		BUG();
>  	}
>  }
>  
> @@ -1826,13 +1828,14 @@ static inline enum dpio_channel
>  vlv_pipe_to_channel(enum pipe pipe)
>  {
>  	switch (pipe) {
> +	default:
> +		MISSING_CASE(pipe);
> +		fallthrough;
>  	case PIPE_A:
>  	case PIPE_C:
>  		return DPIO_CH0;
>  	case PIPE_B:
>  		return DPIO_CH1;
> -	default:
> -		BUG();
>  	}
>  }
>  
> -- 
> 2.30.2

-- 
Ville Syrjälä
Intel