From patchwork Thu Apr 30 12:46:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frieder Schrempf X-Patchwork-Id: 11522187 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 E62B892A for ; Fri, 1 May 2020 07:23:03 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CA4E3208C3 for ; Fri, 1 May 2020 07:23:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CA4E3208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kontron.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7C1F06EA83; Fri, 1 May 2020 07:22:30 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from skedge04.snt-world.com (skedge04.snt-world.com [91.208.41.69]) by gabe.freedesktop.org (Postfix) with ESMTPS id C33826E867; Thu, 30 Apr 2020 12:52:11 +0000 (UTC) Received: from sntmail10s.snt-is.com (unknown [10.203.32.183]) by skedge04.snt-world.com (Postfix) with ESMTP id 1011167A7D8; Thu, 30 Apr 2020 14:46:08 +0200 (CEST) Received: from sntmail12r.snt-is.com (10.203.32.182) by sntmail10s.snt-is.com (10.203.32.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1913.5; Thu, 30 Apr 2020 14:46:07 +0200 Received: from sntmail12r.snt-is.com ([fe80::e551:8750:7bba:3305]) by sntmail12r.snt-is.com ([fe80::e551:8750:7bba:3305%3]) with mapi id 15.01.1913.007; Thu, 30 Apr 2020 14:46:07 +0200 From: Schrempf Frieder To: Adam Ford , Anson Huang , Christian Gmeiner , Daniel Baluta , Fabio Estevam , Schrempf Frieder , Leonard Crestez , "Li Jun" , Lucas Stach , NXP Linux Team , Peng Fan , Pengutronix Kernel Team , Russell King , "Sascha Hauer" , Shawn Guo , "S.j. Wang" Subject: [RFC PATCH 1/4] drm/etnaviv: Prevent IRQ triggering at probe time on i.MX8MM Thread-Topic: [RFC PATCH 1/4] drm/etnaviv: Prevent IRQ triggering at probe time on i.MX8MM Thread-Index: AQHWHu1RaS/QCZFEh0aIMChy0QTuwg== Date: Thu, 30 Apr 2020 12:46:07 +0000 Message-ID: <20200430124602.14463-2-frieder.schrempf@kontron.de> References: <20200430124602.14463-1-frieder.schrempf@kontron.de> In-Reply-To: <20200430124602.14463-1-frieder.schrempf@kontron.de> Accept-Language: de-DE, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: git-send-email 2.17.1 x-originating-ip: [172.25.9.193] x-c2processedorg: 51b406b7-48a2-4d03-b652-521f56ac89f3 MIME-Version: 1.0 X-SnT-MailScanner-Information: Please contact the ISP for more information X-SnT-MailScanner-ID: 1011167A7D8.A1C56 X-SnT-MailScanner: Not scanned: please contact your Internet E-Mail Service Provider for details X-SnT-MailScanner-SpamCheck: X-SnT-MailScanner-From: frieder.schrempf@kontron.de X-SnT-MailScanner-To: aford173@gmail.com, anson.huang@nxp.com, christian.gmeiner@gmail.com, daniel.baluta@nxp.com, devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, etnaviv@lists.freedesktop.org, festevam@gmail.com, jun.li@nxp.com, kernel@pengutronix.de, l.stach@pengutronix.de, leonard.crestez@nxp.com, linux+etnaviv@armlinux.org.uk, linux-arm-kernel@lists.infradead.org, linux-imx@nxp.com, linux-kernel@vger.kernel.org, peng.fan@nxp.com, s.hauer@pengutronix.de, shawnguo@kernel.org, shengjiu.wang@nxp.com X-Spam-Status: No X-Mailman-Approved-At: Fri, 01 May 2020 07:22:25 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , "etnaviv@lists.freedesktop.org" , "dri-devel@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Frieder Schrempf On i.MX8MM there is an interrupt getting triggered immediately after requesting the IRQ, which leads to a stall as the handler accesses the GPU registers whithout the clock being enabled. Enabling the clocks briefly seems to clear the IRQ state, so we do this before requesting the IRQ. Signed-off-by: Frieder Schrempf --- drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 29 ++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c index a31eeff2b297..23877c1f150a 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c @@ -1775,13 +1775,6 @@ static int etnaviv_gpu_platform_probe(struct platform_device *pdev) return gpu->irq; } - err = devm_request_irq(&pdev->dev, gpu->irq, irq_handler, 0, - dev_name(gpu->dev), gpu); - if (err) { - dev_err(dev, "failed to request IRQ%u: %d\n", gpu->irq, err); - return err; - } - /* Get Clocks: */ gpu->clk_reg = devm_clk_get(&pdev->dev, "reg"); DBG("clk_reg: %p", gpu->clk_reg); @@ -1805,6 +1798,28 @@ static int etnaviv_gpu_platform_probe(struct platform_device *pdev) gpu->clk_shader = NULL; gpu->base_rate_shader = clk_get_rate(gpu->clk_shader); + /* + * On i.MX8MM there is an interrupt getting triggered immediately + * after requesting the IRQ, which leads to a stall as the handler + * accesses the GPU registers whithout the clock being enabled. + * Enabling the clocks briefly seems to clear the IRQ state, so we do + * this here before requesting the IRQ. + */ + err = etnaviv_gpu_clk_enable(gpu); + if (err) + return err; + + err = etnaviv_gpu_clk_disable(gpu); + if (err) + return err; + + err = devm_request_irq(&pdev->dev, gpu->irq, irq_handler, 0, + dev_name(gpu->dev), gpu); + if (err) { + dev_err(dev, "failed to request IRQ%u: %d\n", gpu->irq, err); + return err; + } + /* TODO: figure out max mapped size */ dev_set_drvdata(dev, gpu);