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[AMD Official Use Only - Internal Distribution Only]<br>
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This patch introduces a null pointer deref on MST hotplug, so this shall be dropped.<br>
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--</div>
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Thanks & Regards,</div>
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Aurabindo Pillai<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Aurabindo Pillai <aurabindo.pillai@amd.com><br>
<b>Sent:</b> Friday, April 16, 2021 10:34 AM<br>
<b>To:</b> amd-gfx@lists.freedesktop.org <amd-gfx@lists.freedesktop.org><br>
<b>Cc:</b> Wentland, Harry <Harry.Wentland@amd.com>; Li, Sun peng (Leo) <Sunpeng.Li@amd.com>; Lakha, Bhawanpreet <Bhawanpreet.Lakha@amd.com>; Siqueira, Rodrigo <Rodrigo.Siqueira@amd.com>; Pillai, Aurabindo <Aurabindo.Pillai@amd.com>; Zhuo, Qingqing <Qingqing.Zhuo@amd.com>;
Brol, Eryk <Eryk.Brol@amd.com>; R, Bindu <Bindu.R@amd.com>; Jacob, Anson <Anson.Jacob@amd.com>; Zhang, Dingchen (David) <Dingchen.Zhang@amd.com>; Zhang, Dingchen (David) <Dingchen.Zhang@amd.com><br>
<b>Subject:</b> [PATCH 13/19] drm/amd/display: force CP to DESIRED when removing display.</font>
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<div class="PlainText">From: "Dingchen (David) Zhang" <dingchen.zhang@amd.com><br>
<br>
[why]<br>
It is possible that the commit from userspace to cause link stream<br>
disable and hdcp auth reset when the HDCP has been enabled at the<br>
moment. We'd expect the CP prop back to DESIRED from ENABLED.<br>
<br>
[how]<br>
In the helper of hdcp display removal, we check and change the CP prop<br>
to DESIRED if at the moment CP is ENABLED before the auth reset and<br>
removal of linked list element.<br>
<br>
Signed-off-by: Dingchen (David) Zhang <dingchen.zhang@amd.com><br>
Reviewed-by: Dingchen Zhang <Dingchen.Zhang@amd.com><br>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com><br>
---<br>
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c | 13 +++++++++++++<br>
1 file changed, 13 insertions(+)<br>
<br>
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c<br>
index 616f5b1ea3a8..50f6b3a86931 100644<br>
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c<br>
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c<br>
@@ -160,6 +160,7 @@ static void link_lock(struct hdcp_workqueue *work, bool lock)<br>
mutex_unlock(&work[i].mutex);<br>
}<br>
}<br>
+<br>
void hdcp_update_display(struct hdcp_workqueue *hdcp_work,<br>
unsigned int link_index,<br>
struct amdgpu_dm_connector *aconnector,<br>
@@ -222,10 +223,22 @@ static void hdcp_remove_display(struct hdcp_workqueue *hdcp_work,<br>
struct amdgpu_dm_connector *aconnector)<br>
{<br>
struct hdcp_workqueue *hdcp_w = &hdcp_work[link_index];<br>
+ struct drm_connector_state *conn_state = aconnector->base.state;<br>
<br>
mutex_lock(&hdcp_w->mutex);<br>
hdcp_w->aconnector = aconnector;<br>
<br>
+ /* the removal of display will invoke auth reset -> hdcp destroy and<br>
+ * we'd expect the CP prop changed back to DESIRED if at the time ENABLED.<br>
+ * the CP prop change should occur before the element removed from linked list.<br>
+ */<br>
+ if (conn_state && conn_state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED) {<br>
+ conn_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;<br>
+<br>
+ pr_debug("[HDCP_DM] display %d, CP 2 -> 1, type %u, DPMS %u\n",<br>
+ aconnector->base.index, conn_state->hdcp_content_type, aconnector->base.dpms);<br>
+ }<br>
+<br>
mod_hdcp_remove_display(&hdcp_w->hdcp, aconnector->base.index, &hdcp_w->output);<br>
<br>
process_output(hdcp_w);<br>
-- <br>
2.31.1<br>
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