On Thu, 05 May 2022, Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx> wrote:
> On 04/05/2022 19:37, 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.
>>
>> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
>> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>> ---
>> 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 9e6fa59eabba..52cf6fb9994a 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;
>
> No idea of how this "limp" would look in practice and if it is safe.
Worst case it's a black screen I think, but that's infinitely better
than bringing the entire box down.
> Same approach taken elsewhere in the patch so I'm afraid someone with
> display know how will have to look at it.
Cc: Ville.
BR,
Jani.
>
> Regards,
>
> Tvrtko
>
>> @@ -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 0decf3d24237..1a421dda36d7 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 408152f9f46a..8b10ef5153f2 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
>> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
>> @@ -1727,13 +1727,14 @@ 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();
>> }
>> }
>>
>> @@ -1741,13 +1742,14 @@ 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();
>> }
>> }
>>
>> @@ -1755,13 +1757,14 @@ 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();
>> }
>> }
>>
--
Jani Nikula, Intel Open Source Graphics Center
