From f1a277597ffecbac945bd5916308aa61914e7e28 Mon Sep 17 00:00:00 2001 From: Abhijit Kulkarni Date: Sun, 1 Nov 2020 11:29:37 -0800 Subject: [PATCH] disp: msm: sde: delay frame trigger on esd failure This change adds support for delaying kickoff in case of ESD error. This delay is required to handle a race condition between esd workqueue and display thread. When ESD workqueue detects the esd and while handling the failure notification if the new updates arrive on display thread, there is a possibility that ESD workqueue will keep on waiting on pp_done. This could happen if display thread keeps on incrementing the kickoff_cnt before workqueue can check the condition. With this change the kickoff is delayed, allowing the workqueue to get scheduled and avoiding the race condition. Change-Id: I8e6fff5ea5494ae801d1e60ae85b7ad19cc12961 Signed-off-by: Abhijit Kulkarni --- msm/sde/sde_encoder.c | 21 ++++++++++++++++++++- msm/sde/sde_encoder.h | 5 +++++ 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/msm/sde/sde_encoder.c b/msm/sde/sde_encoder.c index 82173054e6..1c09553d84 100644 --- a/msm/sde/sde_encoder.c +++ b/msm/sde/sde_encoder.c @@ -68,6 +68,9 @@ #define EVT_TIME_OUT_SPLIT 2 +/* worst case poll time for delay_kickoff to be cleared */ +#define DELAY_KICKOFF_POLL_TIMEOUT_US 100000 + /* Maximum number of VSYNC wait attempts for RSC state transition */ #define MAX_RSC_WAIT 5 @@ -4173,6 +4176,19 @@ void sde_encoder_kickoff(struct drm_encoder *drm_enc, bool is_error, if (is_error) _sde_encoder_reset_ctl_hw(drm_enc); + if (sde_enc->delay_kickoff) { + u32 loop_count = 20; + u32 sleep = DELAY_KICKOFF_POLL_TIMEOUT_US / loop_count; + + for (i = 0; i < loop_count; i++) { + usleep_range(sleep, sleep * 2); + if (!sde_enc->delay_kickoff) + break; + } + + SDE_EVT32(DRMID(drm_enc), i, SDE_EVTLOG_FUNC_CASE1); + } + /* All phys encs are ready to go, trigger the kickoff */ _sde_encoder_kickoff_phys(sde_enc, config_changed); @@ -5360,6 +5376,7 @@ int sde_encoder_display_failure_notification(struct drm_encoder *enc, event_thread = &priv->event_thread[sde_enc->crtc->index]; if (!skip_pre_kickoff) { + sde_enc->delay_kickoff = true; kthread_queue_work(&event_thread->worker, &sde_enc->esd_trigger_work); kthread_flush_work(&sde_enc->esd_trigger_work); @@ -5372,8 +5389,10 @@ int sde_encoder_display_failure_notification(struct drm_encoder *enc, */ sde_encoder_helper_switch_vsync(enc, true); - if (!skip_pre_kickoff) + if (!skip_pre_kickoff) { sde_encoder_wait_for_event(enc, MSM_ENC_TX_COMPLETE); + sde_enc->delay_kickoff = false; + } return 0; } diff --git a/msm/sde/sde_encoder.h b/msm/sde/sde_encoder.h index 24f66221de..ffce98bcd5 100644 --- a/msm/sde/sde_encoder.h +++ b/msm/sde/sde_encoder.h @@ -189,6 +189,10 @@ struct sde_encoder_ops { * @valid_cpu_mask: actual voted cpu core mask * @mode_info: stores the current mode and should be used * only in commit phase + * @delay_kickoff boolean to delay the kickoff, used in case + * of esd attack to ensure esd workqueue detects + * the previous frame transfer completion before + * next update is triggered. */ struct sde_encoder_virt { struct drm_encoder base; @@ -256,6 +260,7 @@ struct sde_encoder_virt { struct dev_pm_qos_request pm_qos_cpu_req[NR_CPUS]; struct cpumask valid_cpu_mask; struct msm_mode_info mode_info; + bool delay_kickoff; }; #define to_sde_encoder_virt(x) container_of(x, struct sde_encoder_virt, base)