[Intel-gfx] [PATCH 2/2] drm/dp: Wait up all outstanding tx waiters

[Daniel Vetter]

On Sat, May 13, 2017 at 11:52:01AM +0100, Chris Wilson wrote:
> As we can have multiple tx in the queue, with individual waiters, make
> sure that all are woken when any state changes (so that we are sure the
> right owner of the txmsg is woken).
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

I think in practice we need probe vs. the userspace dp aux interface (or
multiple userspace apps beating on this), and on multiple different mst
sinks, but better safe than sorry.

Applied, thanks.
-Daniel
> ---
>  drivers/gpu/drm/drm_dp_mst_topology.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 3bdd314f02b1..222eb1a8549b 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -855,7 +855,7 @@ static void drm_dp_destroy_mst_branch_device(struct kref *kref)
>  	mutex_unlock(&mstb->mgr->qlock);
>  
>  	if (wake_tx)
> -		wake_up(&mstb->mgr->tx_waitq);
> +		wake_up_all(&mstb->mgr->tx_waitq);
>  
>  	kref_put(kref, drm_dp_free_mst_branch_device);
>  }
> @@ -1510,7 +1510,7 @@ static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
>  		if (txmsg->seqno != -1)
>  			txmsg->dst->tx_slots[txmsg->seqno] = NULL;
>  		txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
> -		wake_up(&mgr->tx_waitq);
> +		wake_up_all(&mgr->tx_waitq);
>  	}
>  }
>  
> @@ -2258,7 +2258,7 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
>  		mstb->tx_slots[slot] = NULL;
>  		mutex_unlock(&mgr->qlock);
>  
> -		wake_up(&mgr->tx_waitq);
> +		wake_up_all(&mgr->tx_waitq);
>  	}
>  	return ret;
>  }
> -- 
> 2.11.0
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch