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: 11520181 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 D2A41912 for ; Thu, 30 Apr 2020 12:46:43 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 AF2FF2078D for ; Thu, 30 Apr 2020 12:46:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="aEJwnocJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AF2FF2078D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kontron.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References: Message-ID:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ARmaisQ5lfXsQF/v+TNomE/NLgFE9Kl0/uonnrYZ7aY=; b=aEJwnocJak3YpV hnJC6BqfqBpSL4gm7B5Aszi4gCiX/aPf0ZIcJNgrEjSz/O/eyDWxF7O/4UbZAy707n02fZGTzpOfl LmookJq1ieucpDSUy3tyJkgSiOEdEtHp78JQGetkqGRJ3Rs0X4J59QkzwfKYiK46Na/yA+Vv84PuH M0SV9bbadmSLoPXmoeUNWHG37UHkROy4CNvU9AIyWzGdNHoQwcWS8bR0P5A6r8w1YCYIXiqmQk36I KbuvrUSt2WplL8W5dqBosyib4lXSV97el8AzRzzVNLMod3yHHZcMaMxiXZeACbgRo6FekVWgCHsJY Dy6vYlLVfTLNBW0F8+Xg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jU8aN-0000V8-Pu; Thu, 30 Apr 2020 12:46:39 +0000 Received: from skedge04.snt-world.com ([91.208.41.69]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jU8Zv-000079-PB for linux-arm-kernel@lists.infradead.org; Thu, 30 Apr 2020 12:46:17 +0000 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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200430_054612_153963_1EDBD6DD X-CRM114-Status: GOOD ( 10.07 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low trust [91.208.41.69 listed in list.dnswl.org] -0.0 RCVD_IN_MSPIKE_H2 RBL: Average reputation (+2) [91.208.41.69 listed in wl.mailspike.net] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: 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" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org 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);