From 7a7d6681d5adde7dc7e648dcc6b9e9be6ca93d5d Mon Sep 17 00:00:00 2001 From: Janne Grunau Date: Mon, 28 Apr 2025 13:37:14 +0200 Subject: [PATCH] drm: adp: Handle drm_crtc_vblank_get() errors drm_crtc_vblank_get() may fail when it's called before drm_crtc_vblank_on() on a resetted CRTC. This occurs in drm_crtc_helper_funcs' atomic_flush() calls after drm_atomic_helper_crtc_reset() for example directly after probe. Send the vblank event directly in such cases. Avoids following warning in the subsequent drm_crtc_vblank_put() call from the vblank irq handler as below: adp 228200000.display-pipe: [drm] drm_WARN_ON(atomic_read(&vblank->refcount) == 0) WARNING: CPU: 5 PID: 1206 at drivers/gpu/drm/drm_vblank.c:1247 drm_vblank_put+0x158/0x170 ... Call trace: drm_vblank_put+0x158/0x170 (P) drm_crtc_vblank_put+0x24/0x38 adp_fe_irq+0xd8/0xe8 [adpdrm] __handle_irq_event_percpu+0x94/0x318 handle_irq_event+0x54/0xd0 handle_fasteoi_irq+0xa8/0x240 handle_irq_desc+0x3c/0x68 generic_handle_domain_irq+0x24/0x40 Modifying `crtc->state->event` here is fine as crtc->mutex is locked by the non-async atomic commit. In retrospect this looks so obvious that it doesn't warrant a comment in the file. Signed-off-by: Janne Grunau Reviewed-by: Alyssa Rosenzweig Link: https://lore.kernel.org/r/20250428-drm_adp_fixes-v2-2-912e081e55d8@jannau.net Signed-off-by: Alyssa Rosenzweig --- drivers/gpu/drm/adp/adp_drv.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/adp/adp_drv.c b/drivers/gpu/drm/adp/adp_drv.c index 157298a8ff42..bdf27ee742ea 100644 --- a/drivers/gpu/drm/adp/adp_drv.c +++ b/drivers/gpu/drm/adp/adp_drv.c @@ -331,13 +331,19 @@ static void adp_crtc_atomic_flush(struct drm_crtc *crtc, } writel(ADBE_FIFO_SYNC | frame_num, adp->be + ADBE_FIFO); //FIXME: use adbe flush interrupt - spin_lock_irqsave(&crtc->dev->event_lock, flags); if (crtc->state->event) { - drm_crtc_vblank_get(crtc); - adp->event = crtc->state->event; + struct drm_pending_vblank_event *event = crtc->state->event; + + crtc->state->event = NULL; + spin_lock_irqsave(&crtc->dev->event_lock, flags); + + if (drm_crtc_vblank_get(crtc) != 0) + drm_crtc_send_vblank_event(crtc, event); + else + adp->event = event; + + spin_unlock_irqrestore(&crtc->dev->event_lock, flags); } - crtc->state->event = NULL; - spin_unlock_irqrestore(&crtc->dev->event_lock, flags); } static const struct drm_crtc_funcs adp_crtc_funcs = { -- 2.25.1