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 X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95F43C433E7 for ; Mon, 12 Oct 2020 14:08:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7422420776 for ; Mon, 12 Oct 2020 14:08:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731875AbgJLOIl (ORCPT ); Mon, 12 Oct 2020 10:08:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731843AbgJLOIk (ORCPT ); Mon, 12 Oct 2020 10:08:40 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7810C0613D9 for ; Mon, 12 Oct 2020 07:08:04 -0700 (PDT) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kRyUU-0006e3-Aj; Mon, 12 Oct 2020 16:07:54 +0200 Received: from sha by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1kRyUT-0003JY-O0; Mon, 12 Oct 2020 16:07:53 +0200 Date: Mon, 12 Oct 2020 16:07:53 +0200 From: Sascha Hauer To: Christian Eggers Cc: Mark Brown , Shawn Guo , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] spi: imx: Revert "spi: imx: enable runtime pm support" Message-ID: <20201012140753.GF12463@pengutronix.de> References: <20201009042738.26602-1-ceggers@arri.de> <20201009073944.GA11648@pengutronix.de> <6367849.hfWVFoRi9M@n95hx1g2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6367849.hfWVFoRi9M@n95hx1g2> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 16:05:21 up 235 days, 21:35, 155 users, load average: 0.39, 0.21, 0.16 User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-spi@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org On Fri, Oct 09, 2020 at 09:48:29AM +0200, Christian Eggers wrote: > Hi Sascha, > > On Friday, 9 October 2020, 09:39:44 CEST, Sascha Hauer wrote: > > On Fri, Oct 09, 2020 at 06:27:38AM +0200, Christian Eggers wrote: > > > This reverts commit 525c9e5a32bd7951eae3f06d9d077fea51718a6c. > > > > > > If CONFIG_PM is disabled, the system completely freezes on probe as > > > nothing enables the clock of the SPI peripheral. > > > > Instead of reverting it, why not just fix it? > I expect that 5.9 will be released soon. I think that in this late stage > reverting is more safe than fixing... > > > Normally the device should be brought to active state manually in probe > > before pm_runtime takes over, then CONFIG_PM disabled doesn't hurt. > > Using pm_runtime to put the device to active state initially has the > > problem you describe. > Thanks for the hint. I've no experience in runtime power management. If you > could provide a patch against the current version, I can make a quick test. I > can also try to fix it myself, but this will take until next week. Here we go. The patch basically works, but I am also not very confident with pm_runtime, so please have a close look ;) Sascha -------------------------------8<-------------------------------- >From 6c584eb8a2fbff46bf8bbebae6c10609c169309b Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Mon, 12 Oct 2020 15:59:50 +0200 Subject: [PATCH] spi: imx: fix runtime pm support for !CONFIG_PM 525c9e5a32bd introduced pm_runtime support for the i.MX SPI driver. With this pm_runtime is used to bring up the clocks initially. When CONFIG_PM is disabled the clocks are no longer enabled and the driver doesn't work anymore. Fix this by enabling the clocks in the probe function and telling pm_runtime that the device is active using pm_runtime_set_active(). Fixes: 525c9e5a32bd spi: imx: enable runtime pm support Signed-off-by: Sascha Hauer --- drivers/spi/spi-imx.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 38a5f1304cec..c796e937dc6a 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -1674,15 +1674,18 @@ static int spi_imx_probe(struct platform_device *pdev) goto out_master_put; } - pm_runtime_enable(spi_imx->dev); + ret = clk_prepare_enable(spi_imx->clk_per); + if (ret) + goto out_master_put; + + ret = clk_prepare_enable(spi_imx->clk_ipg); + if (ret) + goto out_put_per; + pm_runtime_set_autosuspend_delay(spi_imx->dev, MXC_RPM_TIMEOUT); pm_runtime_use_autosuspend(spi_imx->dev); - - ret = pm_runtime_get_sync(spi_imx->dev); - if (ret < 0) { - dev_err(spi_imx->dev, "failed to enable clock\n"); - goto out_runtime_pm_put; - } + pm_runtime_set_active(spi_imx->dev); + pm_runtime_enable(spi_imx->dev); spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per); /* @@ -1719,8 +1722,12 @@ static int spi_imx_probe(struct platform_device *pdev) out_runtime_pm_put: pm_runtime_dont_use_autosuspend(spi_imx->dev); - pm_runtime_put_sync(spi_imx->dev); + pm_runtime_set_suspended(&pdev->dev); pm_runtime_disable(spi_imx->dev); + + clk_disable_unprepare(spi_imx->clk_ipg); +out_put_per: + clk_disable_unprepare(spi_imx->clk_per); out_master_put: spi_master_put(master); -- 2.28.0 -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |