linux-kernel - [PATCH v2 3/4] drm/mediatek: Detect CMDQ execution timeout

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210808234733.14782-4-chunkuang.hu@kernel.org>
Date:   Mon,  9 Aug 2021 07:47:32 +0800
From:   Chun-Kuang Hu <chunkuang.hu@...nel.org>
To:     Philipp Zabel <p.zabel@...gutronix.de>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>
Cc:     Yongqiang Niu <yongqiang.niu@...iatek.com>,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-mediatek@...ts.infradead.org,
        Chun-Kuang Hu <chunkuang.hu@...nel.org>
Subject: [PATCH v2 3/4] drm/mediatek: Detect CMDQ execution timeout

CMDQ is used to update display register in vblank period, so
it should be execute in next vblank. If it fail to execute
in next 2 vblank, tiemout happen.

Signed-off-by: Chun-Kuang Hu <chunkuang.hu@...nel.org>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index da92a3fedd0a..ad4c1a3a9294 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -55,6 +55,7 @@ struct mtk_drm_crtc {
 	struct mbox_client		cmdq_cl;
 	struct mbox_chan		*cmdq_chan;
 	u32				cmdq_event;
+	u32				cmdq_vblank_cnt;
 #endif
 
 	struct device			*mmsys_dev;
@@ -269,6 +270,7 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
 	struct mtk_drm_crtc *mtk_crtc = container_of(cl, struct mtk_drm_crtc, cmdq_cl);
 	struct cmdq_cb_data *data = mssg;
 
+	mtk_crtc->cmdq_vblank_cnt = 0;
 	mtk_drm_cmdq_pkt_destroy(mtk_crtc->cmdq_chan, data->pkt);
 }
 #endif
@@ -524,6 +526,11 @@ static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc,
 					    cmdq_handle->pa_base,
 					    cmdq_handle->cmd_buf_size,
 					    DMA_TO_DEVICE);
+		/*
+		 * CMDQ command should execute in next vblank,
+		 * If it fail to execute in next 2 vblank, timeout happen.
+		 */
+		mtk_crtc->cmdq_vblank_cnt = 2;
 		mbox_send_message(mtk_crtc->cmdq_chan, cmdq_handle);
 		mbox_client_txdone(mtk_crtc->cmdq_chan, 0);
 	}
@@ -540,11 +547,14 @@ static void mtk_crtc_ddp_irq(void *data)
 
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
 	if (!priv->data->shadow_register && !mtk_crtc->cmdq_chan)
+		mtk_crtc_ddp_config(crtc, NULL);
+	else if (mtk_crtc->cmdq_vblank_cnt > 0 && --mtk_crtc->cmdq_vblank_cnt == 0)
+		DRM_ERROR("mtk_crtc %d CMDQ execute command timeout!\n",
+			  drm_crtc_index(&mtk_crtc->base));
 #else
 	if (!priv->data->shadow_register)
-#endif
 		mtk_crtc_ddp_config(crtc, NULL);
-
+#endif
 	mtk_drm_finish_page_flip(mtk_crtc);
 }
 
-- 
2.25.1