On Wed, Jan 13, 2021 at 7:51 PM Jani Nikula jani.nikula@linux.intel.com wrote:
On Wed, 13 Jan 2021, Koba Ko koba.ko@canonical.com wrote:
After read the link rate from MST hub, align with maximum source rate.
Signed-off-by: Koba Ko koba.ko@canonical.com
drivers/gpu/drm/drm_dp_mst_topology.c | 8 ++++++++ drivers/gpu/drm/i915/display/intel_dp.c | 7 +++++++ include/drm/drm_dp_helper.h | 8 ++++++++ include/drm/drm_dp_mst_helper.h | 4 ++++ 4 files changed, 27 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
b/drivers/gpu/drm/drm_dp_mst_topology.c
index 6982ecbf30b5..e7ceae97be85 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -3672,6 +3672,10 @@ int drm_dp_mst_topology_mgr_set_mst(struct
drm_dp_mst_topology_mgr *mgr, bool ms
{ int ret = 0; struct drm_dp_mst_branch *mstb = NULL;
unsigned int max_link_rate_tbl[MAX_DRM_DP_MAX_RATE + 1] = {DP_LINK_BW_1_62, DP_LINK_BW_2_7, DP_LINK_BW_5_4,DP_LINK_BW_8_1, DP_LINK_RATE_TABLE};Please no. Read on for why.
mutex_lock(&mgr->payload_lock); mutex_lock(&mgr->lock);@@ -3693,6 +3697,9 @@ int drm_dp_mst_topology_mgr_set_mst(struct
drm_dp_mst_topology_mgr *mgr, bool ms
goto out_unlock; }
if (mgr->max_source_rate < MAX_DRM_DP_MAX_RATE)mgr->dpcd[1] =
max_link_rate_tbl[mgr->max_source_rate];
Make ->max_source_rate the actual physical rate in kHz, and use drm_dp_link_rate_to_bw_code() here.
mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1], mgr->dpcd[2] &
DP_MAX_LANE_COUNT_MASK);
if (mgr->pbn_div == 0) {@@ -5422,6 +5429,7 @@ int drm_dp_mst_topology_mgr_init(struct
drm_dp_mst_topology_mgr *mgr,
mgr->aux = aux; mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes; mgr->max_payloads = max_payloads;
mgr->max_source_rate = MAX_DRM_DP_MAX_RATE; mgr->conn_base_id = conn_base_id; if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 || max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
b/drivers/gpu/drm/i915/display/intel_dp.c
index 469e765a1b7b..a89b4c823123 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -5392,6 +5392,13 @@ intel_dp_configure_mst(struct intel_dp *intel_dp) intel_dp->is_mst = sink_can_mst && i915->params.enable_dp_mst;
if (intel_dp_source_supports_hbr3(intel_dp))intel_dp->mst_mgr.max_source_rate = DRM_DP_MAX_RATE_HBR3;else if (intel_dp_source_supports_hbr2(intel_dp))intel_dp->mst_mgr.max_source_rate = DRM_DP_MAX_RATE_HBR2;elseintel_dp->mst_mgr.max_source_rate = DRM_DP_MAX_RATE_HBR;Whenever this file references a "rate", it's the rate in kHz. This is confusing. Use the rate in kHz.
Also, please look at how intel_dp_source_supports_hbr* are implemented; we already have all the supported source rates cached in intel_dp.
The max source rate is:
intel_dp->source_rates[intel_dp->num_source_rates - 1].No need to do the if ladder here at all. If you like, you can add a helper:
int intel_dp_max_source_rate(struct intel_dp *intel_dp) { return intel_dp->source_rates[intel_dp->num_source_rates - 1]; }
and reuse that in the supports_hbr* functions:
bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp) { return intel_dp_max_source_rate(intel_dp) >= 540000; }
drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);} diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 6236f212da61..ef2b328469cd 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -183,6 +183,14 @@ struct drm_device; #define DP_SUPPORTED_LINK_RATES 0x010 /* eDP 1.4 */ # define DP_MAX_SUPPORTED_RATES 8 /* 16-bit
little-endian */
+enum drm_dp_max_link_rate {
DRM_DP_MAX_RATE_RBR = 0,DRM_DP_MAX_RATE_HBR,DRM_DP_MAX_RATE_HBR2,DRM_DP_MAX_RATE_HBR3,MAX_DRM_DP_MAX_RATE+};
We already have 1) actual physical rates, in kHz, and 2) the DPCD rate codes, such as DP_LINK_BW_1_62.
Do *not* add a third representation. Prefer kHz throughout, and convert to/from the DPCD codes near where they are needed.
/* Multiple stream transport */ #define DP_FAUX_CAP 0x020 /* 1.2 */ # define DP_FAUX_CAP_1 (1 << 0) diff --git a/include/drm/drm_dp_mst_helper.h
b/include/drm/drm_dp_mst_helper.h
index f5e92fe9151c..e7d8c899fea0 100644 --- a/include/drm/drm_dp_mst_helper.h +++ b/include/drm/drm_dp_mst_helper.h @@ -593,6 +593,10 @@ struct drm_dp_mst_topology_mgr { * @max_payloads: maximum number of payloads the GPU can generate. */ int max_payloads;
/*** @max_source_rate: maximum link rate of source.*/int max_source_rate;Again, make this the actual rate in kHz. That's what I'd think it is by reading the comment above anyway.
/** * @conn_base_id: DRM connector ID this mgr is connected to. Only
used
* to build the MST connector path value.-- Jani Nikula, Intel Open Source Graphics Center
Hi Jani, thanks and will send the v2 according to the suggestions.
Thanks *Koba Ko*