From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751507AbdIKUNY (ORCPT ); Mon, 11 Sep 2017 16:13:24 -0400 Received: from fllnx209.ext.ti.com ([198.47.19.16]:31644 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750987AbdIKUNW (ORCPT ); Mon, 11 Sep 2017 16:13:22 -0400 Subject: Re: [PATCH v3 1/2] i2c: davinci: Add PM Runtime Support To: Franklin S Cooper Jr , Sekhar Nori , , , , , , , , References: <20170908175448.3367-1-fcooper@ti.com> <20170908175448.3367-2-fcooper@ti.com> <57153767-6dee-a5b5-548c-f7b0dc104b46@ti.com> From: Grygorii Strashko Message-ID: <94b7a185-4cde-03e6-cc17-f64d5d28c9f2@ti.com> Date: Mon, 11 Sep 2017 15:11:42 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [128.247.59.147] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/11/2017 03:07 PM, Franklin S Cooper Jr wrote: > > > On 09/11/2017 06:29 AM, Sekhar Nori wrote: >> On Friday 08 September 2017 11:24 PM, Franklin S Cooper Jr wrote: >>> 66AK2G has I2C instances that are not apart of the ALWAYS_ON power domain >>> like other Keystone 2 SoCs and OMAPL138. Therefore, pm_runtime >> >> unlike ? >> >>> is required to insure the power domain used by the specific I2C instance is >>> properly turned on along with its functional clock. >>> >>> Signed-off-by: Franklin S Cooper Jr >>> --- >>> Version 3 changes: >>> Remove several statements that set clk to NULL >>> Fix error path >>> >>> drivers/i2c/busses/i2c-davinci.c | 64 +++++++++++++++++++++++++++++++++------- >>> 1 file changed, 53 insertions(+), 11 deletions(-) >> >>> @@ -802,12 +821,22 @@ static int davinci_i2c_probe(struct platform_device *pdev) >>> dev->clk = devm_clk_get(&pdev->dev, NULL); >>> if (IS_ERR(dev->clk)) >>> return PTR_ERR(dev->clk); >>> - clk_prepare_enable(dev->clk); >>> >>> mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); >>> dev->base = devm_ioremap_resource(&pdev->dev, mem); >>> if (IS_ERR(dev->base)) { >>> - r = PTR_ERR(dev->base); >>> + return PTR_ERR(dev->base); >>> + } >>> + >>> + pm_runtime_set_autosuspend_delay(dev->dev, >>> + DAVINCI_I2C_PM_TIMEOUT); >>> + pm_runtime_use_autosuspend(dev->dev); >>> + >>> + pm_runtime_enable(dev->dev); >>> + >>> + r = pm_runtime_get_sync(dev->dev); >>> + if (r < 0) { >>> + dev_err(dev->dev, "failed to runtime_get device: %d\n", r); >>> goto err_unuse_clocks; >> >> You end up doing a pm_runtime_put_sync() on failure here, instead of >> pm_runtime_put_noidle() like rest of the patch. >> >> May be handle this failure here instead of relying on the goto path. > > Ok I think, it's not necessary - pm_runtime_put_sync() can be used in this case (and used the same way in many other drivers). In case, of failure in this place - pm_runtime_put_sync() will just decrement usage counter. >> >>> } >>> >>> @@ -849,27 +878,40 @@ static int davinci_i2c_probe(struct platform_device *pdev) >>> if (r) >>> goto err_unuse_clocks; >>> >>> + pm_runtime_mark_last_busy(dev->dev); >>> + pm_runtime_put_autosuspend(dev->dev); >>> + >>> return 0; >>> >>> err_unuse_clocks: >>> - clk_disable_unprepare(dev->clk); >>> - dev->clk = NULL; >>> + pm_runtime_dont_use_autosuspend(dev->dev); >>> + pm_runtime_put_sync(dev->dev); >>> + pm_runtime_disable(dev->dev); >>> + >>> return r; >>> } >> >> Thanks, >> Sekhar >> -- regards, -grygorii