From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: Wayne Lin <Wayne.Lin@amd.com>
Cc: dri-devel@lists.freedesktop.org, eryk.brol@amd.com,
qingqing.zhuo@amd.com, stable@vger.kernel.org, jerry.zuo@amd.com,
Nicholas.Kazlauskas@amd.com
Subject: Re: [PATCH 1/2] drm/dp_mst: Revise broadcast msg lct & lcr
Date: Mon, 22 Feb 2021 19:02:03 +0200 [thread overview]
Message-ID: <YDPjiz4tiMRo320Q@intel.com> (raw)
In-Reply-To: <20210222040027.23505-2-Wayne.Lin@amd.com>
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?
>
> --
> 2.17.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Ville Syrjälä
Intel
next prev parent reply other threads:[~2021-02-22 17:04 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-22 4:00 [PATCH 0/2] Set CLEAR_PAYLOAD_ID_TABLE as broadcast request Wayne Lin
2021-02-22 4:00 ` [PATCH 1/2] drm/dp_mst: Revise broadcast msg lct & lcr Wayne Lin
2021-02-22 17:02 ` Ville Syrjälä [this message]
2021-02-22 17:09 ` Ville Syrjälä
2021-02-23 5:32 ` Lin, Wayne
2021-02-23 13:26 ` Ville Syrjälä
2021-02-24 9:47 ` Lin, Wayne
2021-02-22 4:00 ` [PATCH 2/2] drm/dp_mst: Set CLEAR_PAYLOAD_ID_TABLE as broadcast Wayne Lin
2021-02-22 17:00 ` Ville Syrjälä
2021-02-23 5:32 ` Lin, Wayne
2021-02-23 13:21 ` Ville Syrjälä
2021-02-24 18:06 ` [PATCH 0/2] Set CLEAR_PAYLOAD_ID_TABLE as broadcast request Lyude Paul
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