On Mon, Feb 22, 2021 at 07:02:03PM +0200, Ville Syrjälä wrote:
On Mon, Feb 22, 2021 at 12:00:26PM +0800, Wayne Lin wrote:
[Why & How] According to DP spec, broadcast message LCT equals to 1 and LCR equals to 6. Current implementation is incorrect. Fix it.
Signed-off-by: Wayne Lin Wayne.Lin@amd.com Cc: stable@vger.kernel.org
drivers/gpu/drm/drm_dp_mst_topology.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 17dbed0a9800..713ef3b42054 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2727,8 +2727,14 @@ static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr, else hdr->broadcast = 0; hdr->path_msg = txmsg->path_msg;
- hdr->lct = mstb->lct;
- hdr->lcr = mstb->lct - 1;
- if (hdr->broadcast) {
hdr->lct = 1;hdr->lcr = 6;- } else {
hdr->lct = mstb->lct;hdr->lcr = mstb->lct - 1;- }
- if (mstb->lct > 1) memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
We should also do something about RAD no?
Just skip the RAD stuff by s/mstb->lct/hdr->lct/ here I guess?