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drm/dp/mst: Handle arbitrary DP_LINK_BW values 

Make drm_dp_get_vc_payload() tolerate arbitrary DP_LINK_BW_*
values, just like drm_dp_bw_code_to_link_rate() does since commit
57a1b08937 ("drm: Make the bw/link rate calculations more forgiving").

Cc: Lyude Paul <lyude@redhat.com>
Cc: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190925141442.23236-2-ville.syrjala@linux.intel.com
Reviewed-by: Lyude Paul <lyude@redhat.com>
This commit is contained in:
Ville Syrjälä 2019-09-25 17:14:41 +03:00
parent db0cc143b6
commit 0c3bb15cfc
1 changed files with 6 additions and 23 deletions
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29
drivers/gpu/drm/drm_dp_mst_topology.c
View File

@ -2977,30 +2977,13 @@ static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
return 0; return 0;
} }
static bool drm_dp_get_vc_payload_bw(int dp_link_bw, static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count)
int dp_link_count,
int *out)
{ {
switch (dp_link_bw) { if (dp_link_bw == 0 || dp_link_count == 0)
default:
DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n", DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
dp_link_bw, dp_link_count); dp_link_bw, dp_link_count);
return false;
case DP_LINK_BW_1_62: return dp_link_bw * dp_link_count / 2;
*out = 3 * dp_link_count;
break;
case DP_LINK_BW_2_7:
*out = 5 * dp_link_count;
break;
case DP_LINK_BW_5_4:
*out = 10 * dp_link_count;
break;
case DP_LINK_BW_8_1:
*out = 15 * dp_link_count;
break;
}
return true;
} }
/** /**
@ -3032,9 +3015,9 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
goto out_unlock; goto out_unlock;
} }
if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1], mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1],
mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK, mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK);
&mgr->pbn_div)) { if (mgr->pbn_div == 0) {
ret = -EINVAL; ret = -EINVAL;
goto out_unlock; goto out_unlock;
} }