From patchwork Tue Jul 7 17:48:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bob Beckett X-Patchwork-Id: 11649499 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DAFCA739 for ; Tue, 7 Jul 2020 17:50:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C74622073E for ; Tue, 7 Jul 2020 17:50:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728238AbgGGRuD (ORCPT ); Tue, 7 Jul 2020 13:50:03 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:35412 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728211AbgGGRuD (ORCPT ); Tue, 7 Jul 2020 13:50:03 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: bbeckett) with ESMTPSA id 6CA042A39FD From: Robert Beckett To: Rob Clark , Sean Paul , David Airlie , Daniel Vetter , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org Cc: Robert Beckett Subject: [RFC PATCH] drm/msm: Add vblank timestamp support for dpu1 Date: Tue, 7 Jul 2020 18:48:51 +0100 Message-Id: <20200707174922.7020-1-bob.beckett@collabora.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org add vblank timestamp support via drm helpers [RFC] some questions about modern vblank timestamp handling in context of this patch: 1. When a driver is using output polling with no console defined and fb helpers trigger an atomic mode set during initial output detection, existing vblank->hwmode.crtc_clock is not set (no current mode). While enabling vblank during the atomic commit we hit a warning in drm_crtc_vblank_helper_get_vblank_timestamp_internal, which has a comment indicating that it is expected to happen during initial modesetting of a crtc. Given this, why is there a WARN_ON_ONCE? If it is expected, warnings just pollute the log and cause alarm. If it is there to warn on any future crtc_clock == 0, the the once version of warn means it wont actually warn as it is disabled during the initial modeset. 2. It looks like drm_calc_timestamping_constants should be called by drivers to set vblank->hwmode. The comment block for drm_crtc_vblank_helper_get_vblank_timestamp_internal suggests that drm_atomic_helper_update_legacy_modeset_state already calls it, yet the comment block before drm_atomic_helper_update_legacy_modeset_state suggests that it should only be used for drivers transitioning from legacy. Where is the ideal place for new implementations to call it? I followed the example of vkms which does it during vblank_enable handler. 3. When calling drm_calc_timestamping_constants, I used crtc->state->adjusted_mode, which seemed like the most appropriate mode for that point in the call chain. Is this the correct thing to use? 4. Is it safe to assume that crtc->mutex will already be held in call calls of vblank_enable in an atomic driver? Signed-off-by: Robert Beckett --- drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 69 +++++++++++++++++++++ drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 7 +++ drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h | 5 ++ drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 10 ++- drivers/gpu/drm/msm/msm_drv.c | 1 + 5 files changed, 91 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c index e15b42a780e0..7f2d9df699e1 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -1320,6 +1320,73 @@ static void dpu_crtc_early_unregister(struct drm_crtc *crtc) debugfs_remove_recursive(dpu_crtc->debugfs_root); } +static struct drm_encoder *get_encoder_from_crtc(struct drm_crtc *crtc) +{ + struct drm_device *dev = crtc->dev; + struct drm_encoder *encoder; + + drm_for_each_encoder(encoder, dev) + if (encoder->crtc == crtc) + return encoder; + + return NULL; +} + +static bool dpu_crtc_get_scanout_position(struct drm_crtc *crtc, + bool in_vblank_irq, + int *vpos, int *hpos, + ktime_t *stime, ktime_t *etime, + const struct drm_display_mode *mode) +{ + unsigned int pipe = crtc->index; + struct drm_encoder *encoder; + int line, vsw, vbp, vactive_start, vactive_end, vfp_end; + + + encoder = get_encoder_from_crtc(crtc); + if (!encoder) { + DRM_ERROR("no encoder found for crtc %d\n", pipe); + return false; + } + + vsw = mode->crtc_vsync_end - mode->crtc_vsync_start; + vbp = mode->crtc_vtotal - mode->crtc_vsync_end; + + /* + * the line counter is 1 at the start of the VSYNC pulse and VTOTAL at + * the end of VFP. Translate the porch values relative to the line + * counter positions. + */ + + vactive_start = vsw + vbp + 1; + + vactive_end = vactive_start + mode->crtc_vdisplay; + + /* last scan line before VSYNC */ + vfp_end = mode->crtc_vtotal; + + if (stime) + *stime = ktime_get(); + + line = dpu_encoder_get_linecount(encoder); + + if (line < vactive_start) + line -= vactive_start; + else if (line > vactive_end) + line = line - vfp_end - vactive_start; + else + line -= vactive_start; + + *vpos = line; + *hpos = 0; + + if (etime) + *etime = ktime_get(); + + return true; +} + + static const struct drm_crtc_funcs dpu_crtc_funcs = { .set_config = drm_atomic_helper_set_config, .destroy = dpu_crtc_destroy, @@ -1331,6 +1398,7 @@ static const struct drm_crtc_funcs dpu_crtc_funcs = { .early_unregister = dpu_crtc_early_unregister, .enable_vblank = msm_crtc_enable_vblank, .disable_vblank = msm_crtc_disable_vblank, + .get_vblank_timestamp = drm_crtc_vblank_helper_get_vblank_timestamp, }; static const struct drm_crtc_helper_funcs dpu_crtc_helper_funcs = { @@ -1339,6 +1407,7 @@ static const struct drm_crtc_helper_funcs dpu_crtc_helper_funcs = { .atomic_check = dpu_crtc_atomic_check, .atomic_begin = dpu_crtc_atomic_begin, .atomic_flush = dpu_crtc_atomic_flush, + .get_scanout_position = dpu_crtc_get_scanout_position, }; /* initialize crtc */ diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c index 0946a86b37b2..c0d95e63dff1 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -1653,6 +1653,13 @@ static u32 _dpu_encoder_calculate_linetime(struct dpu_encoder_virt *dpu_enc, return line_time; } +int dpu_encoder_get_linecount(struct drm_encoder *encoder) +{ + struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(encoder); + + return dpu_enc->cur_master->ops.get_line_count(dpu_enc->cur_master); +} + int dpu_encoder_vsync_time(struct drm_encoder *drm_enc, ktime_t *wakeup_time) { struct drm_display_mode *mode; diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h index b4913465e602..f492ef0a2b2b 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h @@ -85,6 +85,11 @@ void dpu_encoder_trigger_kickoff_pending(struct drm_encoder *encoder); */ void dpu_encoder_kickoff(struct drm_encoder *encoder); +/** + * dpu_encoder_get_linecount - get the current scanline count for this encoder + */ +int dpu_encoder_get_linecount(struct drm_encoder *encoder); + /** * dpu_encoder_wakeup_time - get the time of the next vsync */ diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c index 680527e28d09..96200de57291 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c @@ -13,6 +13,7 @@ #include #include +#include #include "msm_drv.h" #include "msm_mmu.h" @@ -350,6 +351,11 @@ static void dpu_kms_prepare_commit(struct msm_kms *kms, if (!kms) return; + for_each_new_crtc_in_state(state, crtc, crtc_state, i) { + if (crtc_state->mode.crtc_clock) + drm_crtc_vblank_get(crtc); + } + /* Call prepare_commit for all affected encoders */ for_each_new_crtc_in_state(state, crtc, crtc_state, i) { drm_for_each_encoder_mask(encoder, crtc->dev, @@ -402,8 +408,10 @@ static void dpu_kms_complete_commit(struct msm_kms *kms, unsigned crtc_mask) DPU_ATRACE_BEGIN("kms_complete_commit"); - for_each_crtc_mask(dpu_kms->dev, crtc, crtc_mask) + for_each_crtc_mask(dpu_kms->dev, crtc, crtc_mask) { dpu_crtc_complete_commit(crtc); + drm_crtc_vblank_put(crtc); + } DPU_ATRACE_END("kms_complete_commit"); } diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index f6ce40bf3699..e9016b2bfd57 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -679,6 +679,7 @@ int msm_crtc_enable_vblank(struct drm_crtc *crtc) struct msm_kms *kms = priv->kms; if (!kms) return -ENXIO; + drm_calc_timestamping_constants(crtc, &crtc->state->adjusted_mode); DBG("dev=%p, crtc=%u", dev, pipe); return vblank_ctrl_queue_work(priv, pipe, true); }