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

[Andrzej Hajda]

On 31.05.2022 18:25, 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.nik...@intel.com>

All BUG() cases seems to be converted.

Reviewed-by: Andrzej Hajda <andrzej.ha...@intel.com>

Regards
Andrzej

---
  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();
        }
  }