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 2DF35C001DB for ; Thu, 10 Aug 2023 06:42:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231490AbjHJGmY (ORCPT ); Thu, 10 Aug 2023 02:42:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229789AbjHJGmW (ORCPT ); Thu, 10 Aug 2023 02:42:22 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 608C3E4B for ; Wed, 9 Aug 2023 23:42:22 -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 E38626607214; Thu, 10 Aug 2023 07:42:20 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1691649741; bh=AH7PasgmgN1fEaZCrE2ClwlHFqQahh2muQjAvp9GeQ8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=VNRJsYk7VGrAI3ZM3AcUbmIpZYSSS+pkF7xRZCTaNIxhZRo3T/FDtclioONFy8tAY 7NqrObI7Iy02axN1y9764P9w6VUFky0vv8dgyANXQy7qGwPf00e8NzbZX+V35FZJDv hTYhX3RfzADDwgvy7KXl+P+bl/yA6KgAzRORCsDcVyJ42WqZkRYJL85JecDpGppCp+ vACbHTJJdwL/VY3XUyaH3v6LIlIAzFcf8xgR5LyC77iA+sX9PSXceMgJVy1D/br1hY +RDghSC/dHWSAyKXwi1iab01wCYNalvFTolAAxLZzWgrkTXpHItIc7A4X9Wj5uggHF J3+j79CqPzw2A== Date: Thu, 10 Aug 2023 08:42:19 +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 v4] drm/panfrost: Sync IRQ by job's timeout handler Message-ID: <20230810084219.73ca8037@collabora.com> In-Reply-To: <20230807000444.14926-1-dmitry.osipenko@collabora.com> References: <20230807000444.14926-1-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 Mon, 7 Aug 2023 03:04:44 +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: Boris Brezillon > Reviewed-by: AngeloGioacchino Del Regno > Tested-by: AngeloGioacchino Del Regno # MediaTek MT8192 and MT8195 Chromebooks > Signed-off-by: Dmitry Osipenko Queued to drm-misc-next. Thanks, Boris > --- > > Changelog: > > v4: - Improved comment like was suggested by Boris and added his r-b. > > 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 | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c > index dbc597ab46fb..db6d9a17004f 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_job.c > +++ b/drivers/gpu/drm/panfrost/panfrost_job.c > @@ -720,6 +720,22 @@ 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 a long time to process an interrupt > + * if there is another IRQ handler hogging the processing. > + * For example, the HDMI encoder driver might be stuck in the IRQ > + * handler for a significant time in a case of bad 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)),