Some dongle set both link lane and rate to 0 during dpcd receiver capability read if there is no monitor attache to this dongle. Therefore return fail to prevent driver from trying to populate monitor further.
Changes in V2: -- split this patch into two. Move postpone irq_handle into next patch -- add Fixes tag
Fixes: 78f94fbb6122 ("drm/msm/dp: fix connect/disconnect handled at irq_hpd")
Signed-off-by: Kuogee Hsieh khsieh@codeaurora.org --- drivers/gpu/drm/msm/dp/dp_panel.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c index 97dca3e..d1780bc 100644 --- a/drivers/gpu/drm/msm/dp/dp_panel.c +++ b/drivers/gpu/drm/msm/dp/dp_panel.c @@ -167,12 +167,18 @@ int dp_panel_read_sink_caps(struct dp_panel *dp_panel, panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
rc = dp_panel_read_dpcd(dp_panel); + if (rc) { + DRM_ERROR("read dpcd failed %d\n", rc); + return rc; + } + bw_code = drm_dp_link_rate_to_bw_code(dp_panel->link_info.rate); - if (rc || !is_link_rate_valid(bw_code) || + if (!is_link_rate_valid(bw_code) || !is_lane_count_valid(dp_panel->link_info.num_lanes) || (bw_code > dp_panel->max_bw_code)) { - DRM_ERROR("read dpcd failed %d\n", rc); - return rc; + DRM_ERROR("Illegal link rate=%d lane=%d\n", dp_panel->link_info.rate, + dp_panel->link_info.num_lanes); + return -EINVAL; }
if (dp_panel->dfp_present) {