From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E003BC0015E for ; Fri, 21 Jul 2023 19:14:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231912AbjGUTOH (ORCPT ); Fri, 21 Jul 2023 15:14:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231919AbjGUTOG (ORCPT ); Fri, 21 Jul 2023 15:14:06 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0041430E4 for ; Fri, 21 Jul 2023 12:14:04 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 851CF61D02 for ; Fri, 21 Jul 2023 19:14:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92C5AC433C8; Fri, 21 Jul 2023 19:14:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689966844; bh=7AAy/zsIGWhDsGyaCGsrrIAYvAvWdZ43Qi0IoHN7vwk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aILBafmN31q2VB3RcCxCnCFG2NXr2qhHQYOsqRTfowxyxZHoTCyydEKn5iNpOeKoE ACZnOneEcQmy+/mm8TqJZESqtoi97IxaWk6kqiTag+UWd7WLc65KKZ5OwZfDLTyhrH IFVO/NFiax/Y+zpVdvEUodA89ph7nFRt4qOM42/U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "kernelci.org bot" , Brian Norris , Sean Paul Subject: [PATCH 5.15 488/532] drm/rockchip: vop: Leave vblank enabled in self-refresh Date: Fri, 21 Jul 2023 18:06:32 +0200 Message-ID: <20230721160640.993296184@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230721160614.695323302@linuxfoundation.org> References: <20230721160614.695323302@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Brian Norris commit 2bdba9d4a3baa758c2ca7f5b37b35c7b3391dc42 upstream. If we disable vblank when entering self-refresh, vblank APIs (like DRM_IOCTL_WAIT_VBLANK) no longer work. But user space is not aware when we enter self-refresh, so this appears to be an API violation -- that DRM_IOCTL_WAIT_VBLANK fails with EINVAL whenever the display is idle and enters self-refresh. The downstream driver used by many of these systems never used to disable vblank for PSR, and in fact, even upstream, we didn't do that until radically redesigning the state machine in commit 6c836d965bad ("drm/rockchip: Use the helpers for PSR"). Thus, it seems like a reasonable API fix to simply restore that behavior, and leave vblank enabled. Note that this appears to potentially unbalance the drm_crtc_vblank_{off,on}() calls in some cases, but: (a) drm_crtc_vblank_on() documents this as OK and (b) if I do the naive balancing, I find state machine issues such that we're not in sync properly; so it's easier to take advantage of (a). This issue was exposed by IGT's kms_vblank tests, and reported by KernelCI. The bug has been around a while (longer than KernelCI noticed), but was only exposed once self-refresh was bugfixed more recently, and so KernelCI could properly test it. Some other notes in: https://lore.kernel.org/dri-devel/Y6OCg9BPnJvimQLT@google.com/ Re: renesas/master bisection: igt-kms-rockchip.kms_vblank.pipe-A-wait-forked on rk3399-gru-kevin == Backporting notes: == Marking as 'Fixes' commit 6c836d965bad ("drm/rockchip: Use the helpers for PSR"), but it probably depends on commit bed030a49f3e ("drm/rockchip: Don't fully disable vop on self refresh") as well. We also need the previous patch ("drm/atomic: Allow vblank-enabled + self-refresh "disable""), of course. v3: * no update v2: * skip unnecessary lock/unlock Fixes: 6c836d965bad ("drm/rockchip: Use the helpers for PSR") Cc: Reported-by: "kernelci.org bot" Link: https://lore.kernel.org/dri-devel/Y5itf0+yNIQa6fU4@sirena.org.uk/ Signed-off-by: Brian Norris Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20230109171809.v3.2.Ic07cba4ab9a7bd3618a9e4258b8f92ea7d10ae5a@changeid Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c @@ -703,13 +703,13 @@ static void vop_crtc_atomic_disable(stru if (crtc->state->self_refresh_active) rockchip_drm_set_win_enabled(crtc, false); + if (crtc->state->self_refresh_active) + goto out; + mutex_lock(&vop->vop_lock); drm_crtc_vblank_off(crtc); - if (crtc->state->self_refresh_active) - goto out; - /* * Vop standby will take effect at end of current frame, * if dsp hold valid irq happen, it means standby complete. @@ -741,9 +741,9 @@ static void vop_crtc_atomic_disable(stru vop_core_clks_disable(vop); pm_runtime_put(vop->dev); -out: mutex_unlock(&vop->vop_lock); +out: if (crtc->state->event && !crtc->state->active) { spin_lock_irq(&crtc->dev->event_lock); drm_crtc_send_vblank_event(crtc, crtc->state->event);