diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 469d3569d5ca..ca936ef41312 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1178,11 +1178,37 @@ static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb, struct drm_dp_sideband_msg_tx *txmsg) { struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; + unsigned long wait_timeout = msecs_to_jiffies(4000); + unsigned long wait_expires = jiffies + wait_timeout; int ret; - ret = wait_event_timeout(mgr->tx_waitq, - check_txmsg_state(mgr, txmsg), - (4 * HZ)); + for (;;) { + /* + * If the driver provides a way for this, change to + * poll-waiting for the MST reply interrupt if we didn't receive + * it for 50 msec. This would cater for cases where the HPD + * pulse signal got lost somewhere, even though the sink raised + * the corresponding MST interrupt correctly. One example is the + * Club 3D CAC-1557 TypeC -> DP adapter which for some reason + * filters out short pulses with a duration less than ~540 usec. + * + * The poll period is 50 msec to avoid missing an interrupt + * after the sink has cleared it (after a 110msec timeout + * since it raised the interrupt). + */ + ret = wait_event_timeout(mgr->tx_waitq, + check_txmsg_state(mgr, txmsg), + mgr->cbs->poll_hpd_irq ? + msecs_to_jiffies(50) : + wait_timeout); + + if (ret || !mgr->cbs->poll_hpd_irq || + time_after(jiffies, wait_expires)) + break; + + mgr->cbs->poll_hpd_irq(mgr); + } + mutex_lock(&mgr->qlock); if (ret > 0) { if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) { |