On Thu, Aug 24, 2023 at 11:05:03AM +0300, Imre Deak wrote:
> At the moment modesetting pipe C on IVB will fail if pipe B uses 4 FDI
> lanes. Make the BW sharing more dynamic by trying to reduce pipe B's
> link bpp in this case, until pipe B uses only up to 2 FDI lanes.
>
> For this instead of the encoder compute config retry loop - which
> reduced link bpp only for the encoder's pipe - check the overall BW
> limits after all CRTC states have been computed and if the check fails
> reduce the maximum link bpp for a selected pipe (for FDI pipe B or C as
> required) and recompute all the CRTC states. Retry this sequence until
> either the overall BW limit check passes, or further bpp reduction is
> not possible (because all pipes/encoders sharing the link BW reached
> their minimum link bpp).
>
> This change also prepares for an upcoming patch resolving BW limits in
> a similar way on MST links as well.
>
> v2:
> - Rename intel_crtc_state::max_link_bpp to max_link_bpp_x16 and
> intel_link_bw_limits::max_bpp to max_bpp_x16. (Jani)
> - Increase back pipe B's link bpp if earlier it was limited due to
> pipe C and pipe C gets later disabled.
> - Don't assume that a CRTC is already in the atomic state, while
> reducing its link bpp.
> - Add DocBook description to intel_fdi_atomic_check_link().
>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/g4x_hdmi.c | 5 +-
> drivers/gpu/drm/i915/display/intel_atomic.c | 207 ++++++++++++++++++
> drivers/gpu/drm/i915/display/intel_atomic.h | 8 +
> drivers/gpu/drm/i915/display/intel_crt.c | 7 +
> drivers/gpu/drm/i915/display/intel_crtc.c | 1 +
> drivers/gpu/drm/i915/display/intel_display.c | 44 ++--
> drivers/gpu/drm/i915/display/intel_display.h | 4 +
> .../drm/i915/display/intel_display_types.h | 9 +-
> drivers/gpu/drm/i915/display/intel_dp.c | 3 +-
> drivers/gpu/drm/i915/display/intel_fdi.c | 137 ++++++++++--
> drivers/gpu/drm/i915/display/intel_fdi.h | 5 +
> drivers/gpu/drm/i915/display/intel_lvds.c | 9 +-
> drivers/gpu/drm/i915/display/intel_sdvo.c | 9 +-
> 13 files changed, 404 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/g4x_hdmi.c b/drivers/gpu/drm/i915/display/g4x_hdmi.c
> index 634b14116d9dd..ebbceddc13259 100644
> --- a/drivers/gpu/drm/i915/display/g4x_hdmi.c
> +++ b/drivers/gpu/drm/i915/display/g4x_hdmi.c
> @@ -133,8 +133,11 @@ static int g4x_hdmi_compute_config(struct intel_encoder *encoder,
> struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> struct drm_i915_private *i915 = to_i915(encoder->base.dev);
>
> - if (HAS_PCH_SPLIT(i915))
> + if (HAS_PCH_SPLIT(i915)) {
> crtc_state->has_pch_encoder = true;
> + if (!intel_atomic_compute_pipe_bpp(crtc_state))
> + return -EINVAL;
> + }
>
> if (IS_G4X(i915))
> crtc_state->has_hdmi_sink = g4x_compute_has_hdmi_sink(state, crtc);
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c
> index 7cf51dd8c0567..ee4cbf80ddb55 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
Not convinced we should put anything there. I think I mostly managed to
move a bunch or semi-random stuff out now, so all it more or less has is
the struct intel_atomic_state alloc/free stuff.
You have intel_atomic_check() in intel_display.c and the lower level
intel_atomic_check_config() is also there, but now the middle man
intel_atomic_check_config_and_link() ended up in intel_atomic.c for
whatever reason. I'd just shove all of it into intel_display.c.
The patch is also rather massive. Can we try to chunk it up to
eg. something like:
1) add the new infrastructure
2) convert the fdi retry stuff to use the new infrastructure
3) add intel_fdi_add_affected_crtcs() (which seems more or less
independent from the rest of the fdi conversion?)
?
> @@ -38,6 +38,7 @@
> #include "intel_atomic.h"
> #include "intel_cdclk.h"
> #include "intel_display_types.h"
> +#include "intel_fdi.h"
> #include "intel_global_state.h"
> #include "intel_hdcp.h"
> #include "intel_psr.h"
> @@ -358,3 +359,209 @@ intel_atomic_get_crtc_state(struct drm_atomic_state *state,
>
> return to_intel_crtc_state(crtc_state);
> }
> +
> +/**
> + * intel_atomic_compute_pipe_bpp - compute pipe bpp limited by max link bpp
> + * @crtc_state: the crtc state
> + *
> + * Compute the pipe bpp limited by the CRTC's maximum link bpp. Encoders can
> + * call this function during state computation in the simple case where the
> + * link bpp will always match the pipe bpp. This is the case for all non-DP
> + * encoders, while DP encoders will use a link bpp lower than pipe bpp in case
> + * of DSC compression.
> + *
> + * Returns %true in case of success, %false if pipe bpp would need to be
> + * reduced below its valid range.
> + */
> +bool intel_atomic_compute_pipe_bpp(struct intel_crtc_state *crtc_state)
> +{
> + int pipe_bpp = min(crtc_state->pipe_bpp,
> + to_bpp_int(crtc_state->max_link_bpp_x16));
> +
> + pipe_bpp = rounddown(pipe_bpp, 2 * 3);
> +
> + if (pipe_bpp < 6 * 3)
> + return false;
> +
> + crtc_state->pipe_bpp = pipe_bpp;
> +
> + return true;
> +}
> +
> +/**
> + * intel_atomic_reduce_link_bpp - reduce maximum link bpp for a selected pipe
> + * @state: atomic state
> + * @limits: link BW limits
> + * @pipe_mask: mask of pipes to select from
> + * @reason: explanation of why bpp reduction is needed
> + *
> + * Select the pipe from @pipe_mask with the biggest link bpp value and set the
> + * maximum of link bpp in @limits below this value. Modeset the selected pipe,
> + * so that its state will get recomputed.
> + *
> + * This function can be called to resolve a link's BW overallocation by reducing
> + * the link bpp of one pipe on the link and hence reducing the total link BW.
> + *
> + * Returns
> + * - 0 in case of success
> + * - %-EINVAL if no pipe can further reduce its link bpp
> + * - Other negative error, if modesetting the selected pipe failed
> + */
> +int intel_atomic_reduce_link_bpp(struct intel_atomic_state *state,
> + struct intel_link_bw_limits *limits,
> + u8 pipe_mask,
> + const char *reason)
> +{
> + struct drm_i915_private *i915 = to_i915(state->base.dev);
> + enum pipe max_bpp_pipe = INVALID_PIPE;
> + struct intel_crtc *crtc;
> + int max_bpp = 0;
> +
> + for_each_intel_crtc_in_pipe_mask(&i915->drm, crtc, pipe_mask) {
> + struct intel_crtc_state *crtc_state;
> + int pipe_bpp;
> +
> + if (limits->min_bpp_pipes & BIT(crtc->pipe))
> + continue;
> +
> + crtc_state = intel_atomic_get_crtc_state(&state->base,
> + crtc);
> + if (IS_ERR(crtc_state))
> + return PTR_ERR(crtc_state);
> +
> + if (crtc_state->dsc.compression_enable)
> + pipe_bpp = crtc_state->dsc.compressed_bpp;
> + else
> + pipe_bpp = crtc_state->pipe_bpp;
> +
> + if (pipe_bpp > max_bpp) {
> + max_bpp = pipe_bpp;
> + max_bpp_pipe = crtc->pipe;
> + }
> + }
> +
> + if (max_bpp_pipe == INVALID_PIPE)
> + return -EINVAL;
> +
> + limits->max_bpp_x16[max_bpp_pipe] = to_bpp_x16(max_bpp) - 1;
> +
> + return intel_modeset_pipes_in_mask(state, reason,
> + BIT(max_bpp_pipe), false);
> +}
> +
> +static int intel_atomic_check_link(struct intel_atomic_state *state,
> + struct intel_link_bw_limits *limits)
> +{
> + int ret;
> +
> + ret = intel_fdi_atomic_check_link(state, limits);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static bool
> +assert_link_limit_change_valid(struct drm_i915_private *i915,
> + const struct intel_link_bw_limits *old_limits,
> + const struct intel_link_bw_limits *new_limits)
> +{
> + bool bpps_changed = false;
> + enum pipe pipe;
> +
> + for_each_pipe(i915, pipe) {
> + /* The bpp limit can only decrease. */
> + if (drm_WARN_ON(&i915->drm,
> + new_limits->max_bpp_x16[pipe] >
> + old_limits->max_bpp_x16[pipe]))
> + return false;
> +
> + if (new_limits->max_bpp_x16[pipe] <
> + old_limits->max_bpp_x16[pipe])
> + bpps_changed = true;
> + }
> +
> + if (drm_WARN_ON(&i915->drm,
> + !bpps_changed))
> + return false;
> +
> + return true;
> +}
> +
> +static bool
> +reset_link_bpp_limit_to_min(struct intel_atomic_state *state,
> + const struct intel_link_bw_limits *old_limits,
> + struct intel_link_bw_limits *new_limits,
> + enum pipe failed_pipe)
> +{
> + if (failed_pipe == INVALID_PIPE)
> + return false;
> +
> + if (new_limits->min_bpp_pipes & BIT(failed_pipe))
> + return false;
> +
> + if (new_limits->max_bpp_x16[failed_pipe] ==
> + old_limits->max_bpp_x16[failed_pipe])
> + return false;
> +
> + new_limits->max_bpp_x16[failed_pipe] =
> + old_limits->max_bpp_x16[failed_pipe];
> + new_limits->min_bpp_pipes |= BIT(failed_pipe);
> +
> + return true;
> +}
> +
> +/**
> + * intel_atomic_check_config_and_link - compute CRTC configs, resolving any BW limits
> + * @state: atomic state
> + *
> + * Compute the configuration of all CRTCs in @state and resolve any BW
> + * limitations on links shared by these CRTCs.
> + *
> + * Return 0 in case of success, or a negative error code otherwise.
> + */
> +int intel_atomic_check_config_and_link(struct intel_atomic_state *state)
> +{
> + struct drm_i915_private *i915 = to_i915(state->base.dev);
> + struct intel_link_bw_limits new_limits = {};
> + struct intel_link_bw_limits old_limits;
> + enum pipe pipe;
> + int ret;
> +
> + for_each_pipe(i915, pipe)
> + new_limits.max_bpp_x16[pipe] = INT_MAX;
> +
> + old_limits = new_limits;
> +
> + while (true) {
> + enum pipe failed_pipe;
> +
> + ret = intel_atomic_check_config(state, &new_limits,
> + &failed_pipe);
> + if (ret) {
> + if (ret == -EINVAL &&
> + reset_link_bpp_limit_to_min(state,
> + &old_limits,
> + &new_limits,
> + failed_pipe))
> + continue;
> +
> + break;
> + }
> +
> + old_limits = new_limits;
> +
> + ret = intel_atomic_check_link(state, &new_limits);
> + if (ret != -EAGAIN)
> + break;
> +
> + if (!assert_link_limit_change_valid(i915,
> + &old_limits,
> + &new_limits)) {
> + ret = -EINVAL;
> + break;
> + }
> + }
> +
> + return ret;
> +}
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic.h b/drivers/gpu/drm/i915/display/intel_atomic.h
> index e506f6a873447..bbf3595d52c41 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic.h
> +++ b/drivers/gpu/drm/i915/display/intel_atomic.h
> @@ -20,6 +20,7 @@ struct intel_atomic_state;
> struct intel_connector;
> struct intel_crtc;
> struct intel_crtc_state;
> +struct intel_link_bw_limits;
>
> int intel_digital_connector_atomic_get_property(struct drm_connector *connector,
> const struct drm_connector_state *state,
> @@ -52,4 +53,11 @@ struct intel_crtc_state *
> intel_atomic_get_crtc_state(struct drm_atomic_state *state,
> struct intel_crtc *crtc);
>
> +int intel_atomic_reduce_link_bpp(struct intel_atomic_state *state,
> + struct intel_link_bw_limits *limits,
> + u8 pipe_mask,
> + const char *reason);
> +bool intel_atomic_compute_pipe_bpp(struct intel_crtc_state *crtc_state);
> +int intel_atomic_check_config_and_link(struct intel_atomic_state *state);
> +
> #endif /* __INTEL_ATOMIC_H__ */
> diff --git a/drivers/gpu/drm/i915/display/intel_crt.c b/drivers/gpu/drm/i915/display/intel_crt.c
> index f66340b4caf0f..3322080a574e8 100644
> --- a/drivers/gpu/drm/i915/display/intel_crt.c
> +++ b/drivers/gpu/drm/i915/display/intel_crt.c
> @@ -36,6 +36,7 @@
> #include "i915_drv.h"
> #include "i915_irq.h"
> #include "i915_reg.h"
> +#include "intel_atomic.h"
> #include "intel_connector.h"
> #include "intel_crt.h"
> #include "intel_crtc.h"
> @@ -413,6 +414,9 @@ static int pch_crt_compute_config(struct intel_encoder *encoder,
> return -EINVAL;
>
> pipe_config->has_pch_encoder = true;
> + if (!intel_atomic_compute_pipe_bpp(pipe_config))
> + return -EINVAL;
> +
> pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
>
> return 0;
> @@ -435,6 +439,9 @@ static int hsw_crt_compute_config(struct intel_encoder *encoder,
> return -EINVAL;
>
> pipe_config->has_pch_encoder = true;
> + if (!intel_atomic_compute_pipe_bpp(pipe_config))
> + return -EINVAL;
> +
> pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
>
> /* LPT FDI RX only supports 8bpc. */
> diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
> index 182c6dd64f47c..1eda6a9f19aa8 100644
> --- a/drivers/gpu/drm/i915/display/intel_crtc.c
> +++ b/drivers/gpu/drm/i915/display/intel_crtc.c
> @@ -175,6 +175,7 @@ void intel_crtc_state_reset(struct intel_crtc_state *crtc_state,
> crtc_state->hsw_workaround_pipe = INVALID_PIPE;
> crtc_state->scaler_state.scaler_id = -1;
> crtc_state->mst_master_transcoder = INVALID_TRANSCODER;
> + crtc_state->max_link_bpp_x16 = INT_MAX;
> }
>
> static struct intel_crtc *intel_crtc_alloc(void)
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index dbf109a2e738f..32778bd01bb05 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -4641,7 +4641,8 @@ intel_crtc_prepare_cleared_state(struct intel_atomic_state *state,
>
> static int
> intel_modeset_pipe_config(struct intel_atomic_state *state,
> - struct intel_crtc *crtc)
> + struct intel_crtc *crtc,
> + const struct intel_link_bw_limits *limits)
> {
> struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> struct intel_crtc_state *crtc_state =
> @@ -4650,7 +4651,6 @@ intel_modeset_pipe_config(struct intel_atomic_state *state,
> struct drm_connector_state *connector_state;
> int pipe_src_w, pipe_src_h;
> int base_bpp, ret, i;
> - bool retry = true;
>
> crtc_state->cpu_transcoder = (enum transcoder) crtc->pipe;
>
> @@ -4673,6 +4673,17 @@ intel_modeset_pipe_config(struct intel_atomic_state *state,
> if (ret)
> return ret;
>
> + crtc_state->max_link_bpp_x16 = limits->max_bpp_x16[crtc->pipe];
> +
> + if (crtc_state->pipe_bpp > to_bpp_int(crtc_state->max_link_bpp_x16)) {
> + drm_dbg_kms(&i915->drm,
> + "[CRTC:%d:%s] Link bpp limited to %d.%04d\n",
> + crtc->base.base.id, crtc->base.name,
> + to_bpp_int(crtc_state->max_link_bpp_x16),
> + to_bpp_frac_dec(crtc_state->max_link_bpp_x16));
> + crtc_state->bw_constrained = true;
> + }
> +
> base_bpp = crtc_state->pipe_bpp;
>
> /*
> @@ -4714,7 +4725,6 @@ intel_modeset_pipe_config(struct intel_atomic_state *state,
> crtc_state->output_types |= BIT(encoder->type);
> }
>
> -encoder_retry:
> /* Ensure the port clock defaults are reset when retrying. */
> crtc_state->port_clock = 0;
> crtc_state->pixel_multiplier = 1;
> @@ -4754,17 +4764,6 @@ intel_modeset_pipe_config(struct intel_atomic_state *state,
> ret = intel_crtc_compute_config(state, crtc);
> if (ret == -EDEADLK)
> return ret;
> - if (ret == -EAGAIN) {
> - if (drm_WARN(&i915->drm, !retry,
> - "[CRTC:%d:%s] loop in pipe configuration computation\n",
> - crtc->base.base.id, crtc->base.name))
> - return -EINVAL;
> -
> - drm_dbg_kms(&i915->drm, "[CRTC:%d:%s] bw constrained, retrying\n",
> - crtc->base.base.id, crtc->base.name);
> - retry = false;
> - goto encoder_retry;
> - }
> if (ret < 0) {
> drm_dbg_kms(&i915->drm, "[CRTC:%d:%s] config failure: %d\n",
> crtc->base.base.id, crtc->base.name, ret);
> @@ -6206,7 +6205,9 @@ static int intel_bigjoiner_add_affected_crtcs(struct intel_atomic_state *state)
> return 0;
> }
>
> -static int intel_atomic_check_config(struct intel_atomic_state *state)
> +int intel_atomic_check_config(struct intel_atomic_state *state,
> + struct intel_link_bw_limits *limits,
> + enum pipe *failed_pipe)
> {
> struct drm_i915_private *i915 = to_i915(state->base.dev);
> struct intel_crtc_state *new_crtc_state;
> @@ -6214,10 +6215,16 @@ static int intel_atomic_check_config(struct intel_atomic_state *state)
> int ret;
> int i;
>
> + *failed_pipe = INVALID_PIPE;
> +
> ret = intel_bigjoiner_add_affected_crtcs(state);
> if (ret)
> return ret;
>
> + ret = intel_fdi_add_affected_crtcs(state);
> + if (ret)
> + return ret;
> +
> for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
> if (!intel_crtc_needs_modeset(new_crtc_state)) {
> if (intel_crtc_is_bigjoiner_slave(new_crtc_state))
> @@ -6239,7 +6246,7 @@ static int intel_atomic_check_config(struct intel_atomic_state *state)
> if (!new_crtc_state->hw.enable)
> continue;
>
> - ret = intel_modeset_pipe_config(state, crtc);
> + ret = intel_modeset_pipe_config(state, crtc, limits);
> if (ret)
> break;
>
> @@ -6248,6 +6255,9 @@ static int intel_atomic_check_config(struct intel_atomic_state *state)
> break;
> }
>
> + if (ret)
> + *failed_pipe = crtc->pipe;
> +
> return ret;
> }
>
> @@ -6295,7 +6305,7 @@ int intel_atomic_check(struct drm_device *dev,
> return ret;
> }
>
> - ret = intel_atomic_check_config(state);
> + ret = intel_atomic_check_config_and_link(state);
> if (ret)
> goto fail;
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
> index d9a54610d9d5e..2e0535739bd70 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.h
> +++ b/drivers/gpu/drm/i915/display/intel_display.h
> @@ -55,6 +55,7 @@ struct intel_digital_port;
> struct intel_dp;
> struct intel_encoder;
> struct intel_initial_plane_config;
> +struct intel_link_bw_limits;
> struct intel_link_m_n;
> struct intel_plane;
> struct intel_plane_state;
> @@ -391,6 +392,9 @@ enum phy_fia {
> (new_connector_state) = to_intel_digital_connector_state((__state)->base.connectors[__i].new_state), 1))
>
> int intel_atomic_check(struct drm_device *dev, struct drm_atomic_state *state);
> +int intel_atomic_check_config(struct intel_atomic_state *state,
> + struct intel_link_bw_limits *limits,
> + enum pipe *failed_pipe);
> int intel_atomic_add_affected_planes(struct intel_atomic_state *state,
> struct intel_crtc *crtc);
> u8 intel_calc_active_pipes(struct intel_atomic_state *state,
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index b143085b399eb..6f4f46658df22 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -66,6 +66,12 @@ struct intel_tc_port;
> * Display related stuff
> */
>
> +struct intel_link_bw_limits {
> + u8 min_bpp_pipes;
> + /* in 1/16 bpp units */
> + int max_bpp_x16[I915_MAX_PIPES];
> +};
> +
> /* these are outputs from the chip - integrated only
> external chips are via DVO or SDVO output */
> enum intel_output_type {
> @@ -1189,7 +1195,8 @@ struct intel_crtc_state {
> u32 ctrl, div;
> } dsi_pll;
>
> - int pipe_bpp;
> + int max_link_bpp_x16; /* in 1/16 bpp units */
> + int pipe_bpp; /* in 1 bpp units */
> struct intel_link_m_n dp_m_n;
>
> /* m2_n2 for eDP downclock */
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 6637bd4768bf7..48f005932ad8b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2218,7 +2218,8 @@ intel_dp_compute_config_link_bpp_limits(struct intel_dp *intel_dp,
> const struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
> int max_link_bpp_x16;
>
> - max_link_bpp_x16 = to_bpp_x16(limits->pipe.max_bpp);
> + max_link_bpp_x16 = min(crtc_state->max_link_bpp_x16,
> + to_bpp_x16(limits->pipe.max_bpp));
>
> if (!dsc) {
> max_link_bpp_x16 = rounddown(max_link_bpp_x16, to_bpp_x16(2 * 3));
> diff --git a/drivers/gpu/drm/i915/display/intel_fdi.c b/drivers/gpu/drm/i915/display/intel_fdi.c
> index e12b46a84fa11..123ba67f68791 100644
> --- a/drivers/gpu/drm/i915/display/intel_fdi.c
> +++ b/drivers/gpu/drm/i915/display/intel_fdi.c
> @@ -119,6 +119,59 @@ void intel_fdi_link_train(struct intel_crtc *crtc,
> dev_priv->display.funcs.fdi->fdi_link_train(crtc, crtc_state);
> }
>
> +/**
> + * intel_fdi_add_affected_crtcs - add CRTCs on FDI affected by other modeset CRTCs
> + * @state: intel atomic state
> + *
> + * Add a CRTC using FDI to @state if changing another CRTC's FDI BW usage is
> + * known to affect the available FDI BW for the former CRTC. In practice this
> + * means adding CRTC B on IVYBRIDGE if its use of FDI lanes is limited (by
> + * CRTC C) and CRTC C is getting disabled.
> + *
> + * Returns 0 in case of success, or a negative error code otherwise.
> + */
> +int intel_fdi_add_affected_crtcs(struct intel_atomic_state *state)
> +{
> + struct drm_i915_private *i915 = to_i915(state->base.dev);
> + struct intel_crtc_state *old_crtc_state;
> + struct intel_crtc_state *new_crtc_state;
> + struct intel_crtc *crtc;
> +
> + if (!IS_IVYBRIDGE(i915))
> + return 0;
> +
> + crtc = intel_crtc_for_pipe(i915, PIPE_C);
> + new_crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
> +
> + if (!new_crtc_state)
> + return 0;
> +
> + old_crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
> +
> + if (!old_crtc_state->fdi_lanes)
> + return 0;
> +
> + if (!intel_crtc_needs_modeset(new_crtc_state))
> + return 0;
> +
> + if (new_crtc_state->uapi.enable)
> + return 0;
> +
> + crtc = intel_crtc_for_pipe(i915, PIPE_B);
> + new_crtc_state = intel_atomic_get_crtc_state(&state->base, crtc);
> +
> + if (IS_ERR(new_crtc_state))
> + return PTR_ERR(old_crtc_state);
> +
> + old_crtc_state = intel_atomic_get_old_crtc_state(state, crtc);
> + if (!old_crtc_state->fdi_lanes)
> + return 0;
> +
> + return intel_modeset_pipes_in_mask(state,
> + "FDI link BW decrease on pipe C",
> + BIT(PIPE_B), false);
> +}
> +
> /* units of 100MHz */
> static int pipe_required_fdi_lanes(struct intel_crtc_state *crtc_state)
> {
> @@ -129,13 +182,16 @@ static int pipe_required_fdi_lanes(struct intel_crtc_state *crtc_state)
> }
>
> static int ilk_check_fdi_lanes(struct drm_device *dev, enum pipe pipe,
> - struct intel_crtc_state *pipe_config)
> + struct intel_crtc_state *pipe_config,
> + enum pipe *pipe_to_reduce)
> {
> struct drm_i915_private *dev_priv = to_i915(dev);
> struct drm_atomic_state *state = pipe_config->uapi.state;
> struct intel_crtc *other_crtc;
> struct intel_crtc_state *other_crtc_state;
>
> + *pipe_to_reduce = pipe;
> +
> drm_dbg_kms(&dev_priv->drm,
> "checking fdi config on pipe %c, lanes %i\n",
> pipe_name(pipe), pipe_config->fdi_lanes);
> @@ -198,6 +254,9 @@ static int ilk_check_fdi_lanes(struct drm_device *dev, enum pipe pipe,
> if (pipe_required_fdi_lanes(other_crtc_state) > 2) {
> drm_dbg_kms(&dev_priv->drm,
> "fdi link B uses too many lanes to enable link C\n");
> +
> + *pipe_to_reduce = PIPE_B;
> +
> return -EINVAL;
> }
> return 0;
> @@ -238,10 +297,8 @@ int ilk_fdi_compute_config(struct intel_crtc *crtc,
> struct drm_device *dev = crtc->base.dev;
> struct drm_i915_private *i915 = to_i915(dev);
> const struct drm_display_mode *adjusted_mode = &pipe_config->hw.adjusted_mode;
> - int lane, link_bw, fdi_dotclock, ret;
> - bool needs_recompute = false;
> + int lane, link_bw, fdi_dotclock;
>
> -retry:
> /* FDI is a binary signal running at ~2.7GHz, encoding
> * each output octet as 10 bits. The actual frequency
> * is stored as a divider into a 100MHz clock, and the
> @@ -261,25 +318,69 @@ int ilk_fdi_compute_config(struct intel_crtc *crtc,
> intel_link_compute_m_n(pipe_config->pipe_bpp, lane, fdi_dotclock,
> link_bw, &pipe_config->fdi_m_n, false);
>
> - ret = ilk_check_fdi_lanes(dev, crtc->pipe, pipe_config);
> - if (ret == -EDEADLK)
> + return 0;
> +}
> +
> +static int intel_fdi_atomic_check_bw(struct intel_atomic_state *state,
> + struct intel_crtc *crtc,
> + struct intel_crtc_state *pipe_config,
> + struct intel_link_bw_limits *limits)
> +{
> + struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> + enum pipe pipe_to_reduce;
> + int ret;
> +
> + ret = ilk_check_fdi_lanes(&i915->drm, crtc->pipe, pipe_config,
> + &pipe_to_reduce);
> + if (ret != -EINVAL)
> return ret;
>
> - if (ret == -EINVAL && pipe_config->pipe_bpp > 6*3) {
> - pipe_config->pipe_bpp -= 2*3;
> - drm_dbg_kms(&i915->drm,
> - "fdi link bw constraint, reducing pipe bpp to %i\n",
> - pipe_config->pipe_bpp);
> - needs_recompute = true;
> - pipe_config->bw_constrained = true;
> + ret = intel_atomic_reduce_link_bpp(state, limits,
> + BIT(pipe_to_reduce),
> + "FDI link BW");
>
> - goto retry;
> - }
> + return ret ? : -EAGAIN;
> +}
>
> - if (needs_recompute)
> - return -EAGAIN;
> +/**
> + * intel_fdi_atomic_check_link - check all modeset FDI link configuration
> + * @state: intel atomic state
> + * @limits: link BW limits
> + *
> + * Check the link configuration for all modeset FDI outputs. If the
> + * configuration is invalid @limits will be updated if possible to
> + * reduce the total BW, after which the configuration for all CRTCs in
> + * @state must be recomputed with the updated @limits.
> + *
> + * Returns:
> + * - 0 if the confugration is valid
> + * - %-EAGAIN, if the configuration is invalid and @limits got updated
> + * with fallback values with which the configuration of all CRTCs
> + * in @state must be recomputed
> + * - Other negative error, if the configuration is invalid without a
> + * fallback possibility, or the check failed for another reason
> + */
> +int intel_fdi_atomic_check_link(struct intel_atomic_state *state,
> + struct intel_link_bw_limits *limits)
> +{
> + struct intel_crtc *crtc;
> + struct intel_crtc_state *crtc_state;
> + int i;
> +
> + for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
> + int ret;
>
> - return ret;
> + if (!crtc_state->has_pch_encoder ||
> + !intel_crtc_needs_modeset(crtc_state) ||
> + !crtc_state->hw.enable)
> + continue;
> +
> + ret = intel_fdi_atomic_check_bw(state, crtc, crtc_state, limits);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> }
>
> static void cpt_set_fdi_bc_bifurcation(struct drm_i915_private *dev_priv, bool enable)
> diff --git a/drivers/gpu/drm/i915/display/intel_fdi.h b/drivers/gpu/drm/i915/display/intel_fdi.h
> index 1cdb86172702f..eb02b967bb440 100644
> --- a/drivers/gpu/drm/i915/display/intel_fdi.h
> +++ b/drivers/gpu/drm/i915/display/intel_fdi.h
> @@ -8,14 +8,19 @@
>
> enum pipe;
> struct drm_i915_private;
> +struct intel_atomic_state;
> struct intel_crtc;
> struct intel_crtc_state;
> struct intel_encoder;
> +struct intel_link_bw_limits;
>
> +int intel_fdi_add_affected_crtcs(struct intel_atomic_state *state);
> int intel_fdi_link_freq(struct drm_i915_private *i915,
> const struct intel_crtc_state *pipe_config);
> int ilk_fdi_compute_config(struct intel_crtc *intel_crtc,
> struct intel_crtc_state *pipe_config);
> +int intel_fdi_atomic_check_link(struct intel_atomic_state *state,
> + struct intel_link_bw_limits *limits);
> void intel_fdi_normal_train(struct intel_crtc *crtc);
> void ilk_fdi_disable(struct intel_crtc *crtc);
> void ilk_fdi_pll_disable(struct intel_crtc *intel_crtc);
> diff --git a/drivers/gpu/drm/i915/display/intel_lvds.c b/drivers/gpu/drm/i915/display/intel_lvds.c
> index 3ace56979b70e..08dcc2d10a2c1 100644
> --- a/drivers/gpu/drm/i915/display/intel_lvds.c
> +++ b/drivers/gpu/drm/i915/display/intel_lvds.c
> @@ -425,6 +425,12 @@ static int intel_lvds_compute_config(struct intel_encoder *encoder,
> return -EINVAL;
> }
>
> + if (HAS_PCH_SPLIT(i915)) {
> + crtc_state->has_pch_encoder = true;
> + if (!intel_atomic_compute_pipe_bpp(crtc_state))
> + return -EINVAL;
> + }
> +
> if (lvds_encoder->a3_power == LVDS_A3_POWER_UP)
> lvds_bpp = 8*3;
> else
> @@ -453,9 +459,6 @@ static int intel_lvds_compute_config(struct intel_encoder *encoder,
> if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
> return -EINVAL;
>
> - if (HAS_PCH_SPLIT(i915))
> - crtc_state->has_pch_encoder = true;
> -
> ret = intel_panel_fitting(crtc_state, conn_state);
> if (ret)
> return ret;
> diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c b/drivers/gpu/drm/i915/display/intel_sdvo.c
> index 7d25a64698e2f..1c6330151f4d6 100644
> --- a/drivers/gpu/drm/i915/display/intel_sdvo.c
> +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c
> @@ -1352,14 +1352,17 @@ static int intel_sdvo_compute_config(struct intel_encoder *encoder,
> struct drm_display_mode *adjusted_mode = &pipe_config->hw.adjusted_mode;
> struct drm_display_mode *mode = &pipe_config->hw.mode;
>
> + if (HAS_PCH_SPLIT(to_i915(encoder->base.dev))) {
> + pipe_config->has_pch_encoder = true;
> + if (!intel_atomic_compute_pipe_bpp(pipe_config))
> + return -EINVAL;
> + }
> +
> DRM_DEBUG_KMS("forcing bpc to 8 for SDVO\n");
> pipe_config->pipe_bpp = 8*3;
> pipe_config->sink_format = INTEL_OUTPUT_FORMAT_RGB;
> pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
>
> - if (HAS_PCH_SPLIT(to_i915(encoder->base.dev)))
> - pipe_config->has_pch_encoder = true;
> -
> /*
> * We need to construct preferred input timings based on our
> * output timings. To do that, we have to set the output
> --
> 2.37.2
--
Ville Syrjälä
Intel
