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 BA2A0EB64DD for ; Tue, 1 Aug 2023 07:50:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232016AbjHAHua (ORCPT ); Tue, 1 Aug 2023 03:50:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231426AbjHAHu2 (ORCPT ); Tue, 1 Aug 2023 03:50:28 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 063E7E48 for ; Tue, 1 Aug 2023 00:50:26 -0700 (PDT) Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by madras.collabora.co.uk (Postfix) with ESMTPSA id 23EDA6607114; Tue, 1 Aug 2023 08:50:25 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1690876225; bh=iODfF7XpW1EtsCvou+Devm/e/p/QPQYfgNk+Z1DVjng=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=D/oZP2a5vFfgDDUfIzfF5DzBwrLULG3v1/Sezkd70rrwoX1vyCZzpTc9/f9pmnVct dwCjBNMmEwYbgc7qN6ubpng/JCYGyJ78yQTvAqcawXXJ8kCL/t56opiApGTX+XP3dU DHYmNOJOjSd2Nta4XyX7gZnbQBIdDrfhu+JHRlOYHtvLr5Gh44j3xBN/hOkrfjBNII 4s43I8Hlff1HRwLq9Axi9PN24KENrjDgDJCSraSg7Omae63+qWlHKtixY9GZmQfQcl 5NzI73Hn4xlaJ1gL2LO6jH/QCRCrN8sJzxwx3w98BLqoV1H+T1y3pQFzy9+nfGqQTu 0diEgd1ZKon4g== Date: Tue, 1 Aug 2023 09:50:22 +0200 From: Boris Brezillon To: Dmitry Osipenko Cc: AngeloGioacchino Del Regno , Rob Herring , Steven Price , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com Subject: Re: [PATCH v3] drm/panfrost: Sync IRQ by job's timeout handler Message-ID: <20230801095022.2c5e66d6@collabora.com> In-Reply-To: <20230801001427.176981-1-dmitry.osipenko@collabora.com> References: <20230801001427.176981-1-dmitry.osipenko@collabora.com> Organization: Collabora X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 1 Aug 2023 03:14:27 +0300 Dmitry Osipenko wrote: > Panfrost IRQ handler may stuck for a long time, for example this happens > when there is a bad HDMI connection and HDMI handler takes a long time to > finish processing, holding Panfrost. Make Panfrost's job timeout handler > to sync IRQ before checking fence signal status in order to prevent > spurious job timeouts due to a slow IRQ processing. > > Reviewed-by: Steven Price > Reviewed-by: AngeloGioacchino Del Regno > Tested-by: AngeloGioacchino Del Regno # MediaTek MT8192 and MT8195 Chromebooks: > Signed-off-by: Dmitry Osipenko Reviewed-by: Boris Brezillon Just a couple nits below. > --- > > Changelog: > > v3: - Added comment to the code as was suggested by Boris > > - Added r-b/t-b from Steven and Angelo > > v2: - Moved synchronize_irq() after first signal-check to avoid unnecessary > blocking on syncing. > > - Added warn message about high interrupt latency. > > drivers/gpu/drm/panfrost/panfrost_job.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c > index dbc597ab46fb..ea1149354f9d 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_job.c > +++ b/drivers/gpu/drm/panfrost/panfrost_job.c > @@ -720,6 +720,21 @@ static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job > if (dma_fence_is_signaled(job->done_fence)) > return DRM_GPU_SCHED_STAT_NOMINAL; > > + /* > + * Panfrost IRQ handler may take long time to process if there is ^ may take a long time to process an interrupt if there is ... > + * another IRQ handler hogging the processing. For example, HDMI > + * may stuck in IRQ handler for a significant time in a case of bad For example, the HDMI encoder driver might be stuck in the IRQ handler ... > + * cable connection. In order to catch such cases and not report > + * spurious Panfrost job timeouts, synchronize the IRQ handler and > + * re-check the fence status. > + */ > + synchronize_irq(pfdev->js->irq); > + > + if (dma_fence_is_signaled(job->done_fence)) { > + dev_warn(pfdev->dev, "unexpectedly high interrupt latency\n"); > + return DRM_GPU_SCHED_STAT_NOMINAL; > + } > + > dev_err(pfdev->dev, "gpu sched timeout, js=%d, config=0x%x, status=0x%x, head=0x%x, tail=0x%x, sched_job=%p", > js, > job_read(pfdev, JS_CONFIG(js)),