From 43181da2a11a3ea335234573f15fddb3e276eb0d Mon Sep 17 00:00:00 2001 From: Dhaval Patel Date: Thu, 3 Mar 2016 13:50:52 -0800 Subject: [PATCH] msm: mdss: fix mdp busy wait race condition DSI software does not wait for MDP_DONE ISR before sending new frame if burst mode feature is enabled. It leads to race condition in below case * MDP kicks off frame-N and mdp_busy sets to true * MDP receives new frame-N+1 and waits for PP_DONE interrupt before sending N+1 frame. * MDP receives PP_DONE interrupt and kicks off frame-N+1 (DSI_MDP_DONE interrupt is not received yet). * Frame-N+1 kickoff sets the mdp_busy wait to true. * DSI receives DSI_MDP_DONE interrupt for frame-N and reset the mdp_busy to false. * Any clock off call can turn off the clock at this moment. DSI software must always execute busy_wait when kickoff happens from mdp. That avoids the busy wait race condition. Change-Id: I462cd5ad21d6ccc08dfb862e98fd6fafeef686d4 Signed-off-by: Dhaval Patel --- drivers/video/fbdev/msm/mdss_dsi_host.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/video/fbdev/msm/mdss_dsi_host.c b/drivers/video/fbdev/msm/mdss_dsi_host.c index f0652870c582..8a552c09544f 100644 --- a/drivers/video/fbdev/msm/mdss_dsi_host.c +++ b/drivers/video/fbdev/msm/mdss_dsi_host.c @@ -2487,8 +2487,7 @@ int mdss_dsi_cmdlist_commit(struct mdss_dsi_ctrl_pdata *ctrl, int from_mdp) if (req && (req->flags & CMD_REQ_HS_MODE)) hs_req = true; - if (!ctrl->burst_mode_enabled || - (from_mdp && ctrl->shared_data->cmd_clk_ln_recovery_en)) { + if ((!ctrl->burst_mode_enabled) || from_mdp) { /* make sure dsi_cmd_mdp is idle */ mdss_dsi_cmd_mdp_busy(ctrl); }