diff options
Diffstat (limited to 'drivers/gpu/drm/display/drm_dp_mst_topology.c')
-rw-r--r-- | drivers/gpu/drm/display/drm_dp_mst_topology.c | 234 |
1 files changed, 181 insertions, 53 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index 0e0d0e76de06..8ca01a6bf645 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -43,6 +43,7 @@ #include <drm/drm_atomic_helper.h> #include <drm/drm_drv.h> #include <drm/drm_edid.h> +#include <drm/drm_fixed.h> #include <drm/drm_print.h> #include <drm/drm_probe_helper.h> @@ -3578,16 +3579,26 @@ static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, * value is in units of PBNs/(timeslots/1 MTP). This value can be used to * convert the number of PBNs required for a given stream to the number of * timeslots this stream requires in each MTP. + * + * Returns the BW / timeslot value in 20.12 fixed point format. */ -int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, - int link_rate, int link_lane_count) +fixed20_12 drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, + int link_rate, int link_lane_count) { + int ch_coding_efficiency = + drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(link_rate)); + fixed20_12 ret; + if (link_rate == 0 || link_lane_count == 0) drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n", link_rate, link_lane_count); - /* See DP v2.0 2.6.4.2, VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ - return link_rate * link_lane_count / 54000; + /* See DP v2.0 2.6.4.2, 2.7.6.3 VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ + ret.full = DIV_ROUND_DOWN_ULL(mul_u32_u32(link_rate * link_lane_count, + ch_coding_efficiency), + (1000000ULL * 8 * 5400) >> 12); + + return ret; } EXPORT_SYMBOL(drm_dp_get_vc_payload_bw); @@ -4335,7 +4346,7 @@ int drm_dp_atomic_find_time_slots(struct drm_atomic_state *state, } } - req_slots = DIV_ROUND_UP(pbn, topology_state->pbn_div); + req_slots = DIV_ROUND_UP(dfixed_const(pbn), topology_state->pbn_div.full); drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] TU %d -> %d\n", port->connector->base.id, port->connector->name, @@ -4718,35 +4729,36 @@ EXPORT_SYMBOL(drm_dp_check_act_status); /** * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. - * @clock: dot clock for the mode - * @bpp: bpp for the mode. - * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel + * @clock: dot clock + * @bpp: bpp as .4 binary fixed point * * This uses the formula in the spec to calculate the PBN value for a mode. */ -int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc) +int drm_dp_calc_pbn_mode(int clock, int bpp) { /* - * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on * common multiplier to render an integer PBN for all link rate/lane * counts combinations * calculate - * peak_kbps *= (1006/1000) - * peak_kbps *= (64/54) - * peak_kbps *= 8 convert to bytes - * - * If the bpp is in units of 1/16, further divide by 16. Put this - * factor in the numerator rather than the denominator to avoid - * integer overflow + * peak_kbps = clock * bpp / 16 + * peak_kbps *= SSC overhead / 1000000 + * peak_kbps /= 8 convert to Kbytes + * peak_kBps *= (64/54) / 1000 convert to PBN */ + /* + * TODO: Use the actual link and mode parameters to calculate + * the overhead. For now it's assumed that these are + * 4 link lanes, 4096 hactive pixels, which don't add any + * significant data padding overhead and that there is no DSC + * or FEC overhead. + */ + int overhead = drm_dp_bw_overhead(4, 4096, 0, bpp, + DRM_DP_BW_OVERHEAD_MST | + DRM_DP_BW_OVERHEAD_SSC_REF_CLK); - if (dsc) - return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006), - 8 * 54 * 1000 * 1000); - - return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006), - 8 * 54 * 1000 * 1000); + return DIV64_U64_ROUND_UP(mul_u32_u32(clock * bpp, 64 * overhead >> 4), + 1000000ULL * 8 * 54 * 1000); } EXPORT_SYMBOL(drm_dp_calc_pbn_mode); @@ -4871,7 +4883,8 @@ void drm_dp_mst_dump_topology(struct seq_file *m, state = to_drm_dp_mst_topology_state(mgr->base.state); seq_printf(m, "\n*** Atomic state info ***\n"); seq_printf(m, "payload_mask: %x, max_payloads: %d, start_slot: %u, pbn_div: %d\n", - state->payload_mask, mgr->max_payloads, state->start_slot, state->pbn_div); + state->payload_mask, mgr->max_payloads, state->start_slot, + dfixed_trunc(state->pbn_div)); seq_printf(m, "\n| idx | port | vcpi | slots | pbn | dsc | status | sink name |\n"); for (i = 0; i < mgr->max_payloads; i++) { @@ -5136,13 +5149,67 @@ static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, return false; } +static bool +drm_dp_mst_port_downstream_of_parent_locked(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port, + struct drm_dp_mst_port *parent) +{ + if (!mgr->mst_primary) + return false; + + port = drm_dp_mst_topology_get_port_validated_locked(mgr->mst_primary, + port); + if (!port) + return false; + + if (!parent) + return true; + + parent = drm_dp_mst_topology_get_port_validated_locked(mgr->mst_primary, + parent); + if (!parent) + return false; + + if (!parent->mstb) + return false; + + return drm_dp_mst_port_downstream_of_branch(port, parent->mstb); +} + +/** + * drm_dp_mst_port_downstream_of_parent - check if a port is downstream of a parent port + * @mgr: MST topology manager + * @port: the port being looked up + * @parent: the parent port + * + * The function returns %true if @port is downstream of @parent. If @parent is + * %NULL - denoting the root port - the function returns %true if @port is in + * @mgr's topology. + */ +bool +drm_dp_mst_port_downstream_of_parent(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port, + struct drm_dp_mst_port *parent) +{ + bool ret; + + mutex_lock(&mgr->lock); + ret = drm_dp_mst_port_downstream_of_parent_locked(mgr, port, parent); + mutex_unlock(&mgr->lock); + + return ret; +} +EXPORT_SYMBOL(drm_dp_mst_port_downstream_of_parent); + static int drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, - struct drm_dp_mst_topology_state *state); + struct drm_dp_mst_topology_state *state, + struct drm_dp_mst_port **failing_port); static int drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, - struct drm_dp_mst_topology_state *state) + struct drm_dp_mst_topology_state *state, + struct drm_dp_mst_port **failing_port) { struct drm_dp_mst_atomic_payload *payload; struct drm_dp_mst_port *port; @@ -5171,7 +5238,7 @@ drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb); list_for_each_entry(port, &mstb->ports, next) { - ret = drm_dp_mst_atomic_check_port_bw_limit(port, state); + ret = drm_dp_mst_atomic_check_port_bw_limit(port, state, failing_port); if (ret < 0) return ret; @@ -5183,7 +5250,8 @@ drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, static int drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, - struct drm_dp_mst_topology_state *state) + struct drm_dp_mst_topology_state *state, + struct drm_dp_mst_port **failing_port) { struct drm_dp_mst_atomic_payload *payload; int pbn_used = 0; @@ -5204,13 +5272,15 @@ drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] no BW available for the port\n", port->parent, port); + *failing_port = port; return -EINVAL; } pbn_used = payload->pbn; } else { pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb, - state); + state, + failing_port); if (pbn_used <= 0) return pbn_used; } @@ -5219,6 +5289,7 @@ drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n", port->parent, port, pbn_used, port->full_pbn); + *failing_port = port; return -ENOSPC; } @@ -5271,10 +5342,10 @@ drm_dp_mst_atomic_check_payload_alloc_limits(struct drm_dp_mst_topology_mgr *mgr } if (!payload_count) - mst_state->pbn_div = 0; + mst_state->pbn_div.full = dfixed_const(0); drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p TU pbn_div=%d avail=%d used=%d\n", - mgr, mst_state, mst_state->pbn_div, avail_slots, + mgr, mst_state, dfixed_trunc(mst_state->pbn_div), avail_slots, mst_state->total_avail_slots - avail_slots); return 0; @@ -5397,19 +5468,81 @@ int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state, EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc); /** + * drm_dp_mst_atomic_check_mgr - Check the atomic state of an MST topology manager + * @state: The global atomic state + * @mgr: Manager to check + * @mst_state: The MST atomic state for @mgr + * @failing_port: Returns the port with a BW limitation + * + * Checks the given MST manager's topology state for an atomic update to ensure + * that it's valid. This includes checking whether there's enough bandwidth to + * support the new timeslot allocations in the atomic update. + * + * Any atomic drivers supporting DP MST must make sure to call this or + * the drm_dp_mst_atomic_check() function after checking the rest of their state + * in their &drm_mode_config_funcs.atomic_check() callback. + * + * See also: + * drm_dp_mst_atomic_check() + * drm_dp_atomic_find_time_slots() + * drm_dp_atomic_release_time_slots() + * + * Returns: + * - 0 if the new state is valid + * - %-ENOSPC, if the new state is invalid, because of BW limitation + * @failing_port is set to: + * - The non-root port where a BW limit check failed + * with all the ports downstream of @failing_port passing + * the BW limit check. + * The returned port pointer is valid until at least + * one payload downstream of it exists. + * - %NULL if the BW limit check failed at the root port + * with all the ports downstream of the root port passing + * the BW limit check. + * - %-EINVAL, if the new state is invalid, because the root port has + * too many payloads. + */ +int drm_dp_mst_atomic_check_mgr(struct drm_atomic_state *state, + struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_topology_state *mst_state, + struct drm_dp_mst_port **failing_port) +{ + int ret; + + *failing_port = NULL; + + if (!mgr->mst_state) + return 0; + + mutex_lock(&mgr->lock); + ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, + mst_state, + failing_port); + mutex_unlock(&mgr->lock); + + if (ret < 0) + return ret; + + return drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state); +} +EXPORT_SYMBOL(drm_dp_mst_atomic_check_mgr); + +/** * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an * atomic update is valid * @state: Pointer to the new &struct drm_dp_mst_topology_state * * Checks the given topology state for an atomic update to ensure that it's - * valid. This includes checking whether there's enough bandwidth to support - * the new timeslot allocations in the atomic update. + * valid, calling drm_dp_mst_atomic_check_mgr() for all MST manager in the + * atomic state. This includes checking whether there's enough bandwidth to + * support the new timeslot allocations in the atomic update. * * Any atomic drivers supporting DP MST must make sure to call this after * checking the rest of their state in their * &drm_mode_config_funcs.atomic_check() callback. * * See also: + * drm_dp_mst_atomic_check_mgr() * drm_dp_atomic_find_time_slots() * drm_dp_atomic_release_time_slots() * @@ -5424,21 +5557,11 @@ int drm_dp_mst_atomic_check(struct drm_atomic_state *state) int i, ret = 0; for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { - if (!mgr->mst_state) - continue; + struct drm_dp_mst_port *tmp_port; - ret = drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state); + ret = drm_dp_mst_atomic_check_mgr(state, mgr, mst_state, &tmp_port); if (ret) break; - - mutex_lock(&mgr->lock); - ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, - mst_state); - mutex_unlock(&mgr->lock); - if (ret < 0) - break; - else - ret = 0; } return ret; @@ -5894,6 +6017,7 @@ static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port) struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) { struct drm_dp_mst_port *immediate_upstream_port; + struct drm_dp_aux *immediate_upstream_aux; struct drm_dp_mst_port *fec_port; struct drm_dp_desc desc = {}; u8 endpoint_fec; @@ -5958,21 +6082,25 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) * - Port is on primary branch device * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG) */ - if (drm_dp_read_desc(port->mgr->aux, &desc, true)) + if (immediate_upstream_port) + immediate_upstream_aux = &immediate_upstream_port->aux; + else + immediate_upstream_aux = port->mgr->aux; + + if (drm_dp_read_desc(immediate_upstream_aux, &desc, true)) return NULL; - if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) && - port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 && - port->parent == port->mgr->mst_primary) { + if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD)) { u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; - if (drm_dp_read_dpcd_caps(port->mgr->aux, dpcd_ext) < 0) + if (drm_dp_read_dpcd_caps(immediate_upstream_aux, dpcd_ext) < 0) return NULL; - if ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) && + if (dpcd_ext[DP_DPCD_REV] >= DP_DPCD_REV_14 && + ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) && ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) - != DP_DWN_STRM_PORT_TYPE_ANALOG)) - return port->mgr->aux; + != DP_DWN_STRM_PORT_TYPE_ANALOG))) + return immediate_upstream_aux; } /* |