From patchwork Tue Oct 27 13:49:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 307297 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 E352CC6379D for ; Tue, 27 Oct 2020 16:46:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B514F22263 for ; Tue, 27 Oct 2020 16:46:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603817195; bh=hee3vS4xuxMewJIgjLMyatYaNaxjQVs7SmePoBuLgQc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nJkvuWIbX3JOouQ0xKY7o0/pX0x0h6AlVlktyjM0sxUrJuR8ihR6do8zgPinRvxyp FG/n99QwKr2i/Y0DX7ekxv77tqLZETmuKN+/4WWOvTYd4vlR6tEhWsZPWmU/HsGgEU 8xjXfsyT1nltnrzTxN+nZJ++JMg8QdrgdaRG9GVI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S368818AbgJ0Plp (ORCPT ); Tue, 27 Oct 2020 11:41:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:53956 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1800260AbgJ0Pf3 (ORCPT ); Tue, 27 Oct 2020 11:35:29 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4F6DA22264; Tue, 27 Oct 2020 15:35:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603812928; bh=hee3vS4xuxMewJIgjLMyatYaNaxjQVs7SmePoBuLgQc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E7qLdukslXruOfsZLy8eOH6/4mxSa8YedMyku59ZDcSbTbB3C8ErJilU4/u1iM0lh YkcLaLhm9NGG2rLqjTNDG7KYxxjEQ2HRaaaNPaDqXlikVEgR/5geo+m/f2jWDLSJSh R3bFfa0f7vGPoYwvllbwwmzvY+Fs6M38VXTbv2O0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Fabrice Gasnier , Ulf Hansson , Jonathan Cameron , Sasha Levin Subject: [PATCH 5.9 348/757] iio: adc: stm32-adc: fix runtime autosuspend delay when slow polling Date: Tue, 27 Oct 2020 14:49:58 +0100 Message-Id: <20201027135506.890447783@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135450.497324313@linuxfoundation.org> References: <20201027135450.497324313@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Fabrice Gasnier [ Upstream commit c537d3457542a398caa1fe58e0976c5f83cf7281 ] When the ADC is runtime suspended and starting a conversion, the stm32-adc driver calls pm_runtime_get_sync() that gets cascaded to the parent (e.g. runtime resume of stm32-adc-core driver). This also kicks the autosuspend delay (e.g. 2s) of the parent. Once the ADC is active, calling pm_runtime_get_sync() again (upon a new capture) won't kick the autosuspend delay for the parent (stm32-adc-core driver) as already active. Currently, this makes the stm32-adc-core driver go in suspend state every 2s when doing slow polling. As an example, doing a capture, e.g. cat in_voltageY_raw at a 0.2s rate, the auto suspend delay for the parent isn't refreshed. Once it expires, the parent immediately falls into runtime suspended state, in between two captures, as soon as the child driver falls into runtime suspend state: - e.g. after 2s, + child calls pm_runtime_put_autosuspend() + 100ms autosuspend delay of the child. - stm32-adc-core switches off regulators, clocks and so on. - They get switched on back again 100ms later in this example (at 2.2s). So, use runtime_idle() callback in stm32-adc-core driver to call pm_runtime_mark_last_busy() for the parent driver (stm32-adc-core), to avoid this. Fixes: 9bdbb1139ca1 ("iio: adc: stm32-adc: add power management support") Signed-off-by: Fabrice Gasnier Reviewed-by: Ulf Hansson Link: https://lore.kernel.org/r/1593615328-5180-1-git-send-email-fabrice.gasnier@st.com Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/iio/adc/stm32-adc-core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c index 0e2068ec068b8..358636954619d 100644 --- a/drivers/iio/adc/stm32-adc-core.c +++ b/drivers/iio/adc/stm32-adc-core.c @@ -794,6 +794,13 @@ static int stm32_adc_core_runtime_resume(struct device *dev) { return stm32_adc_core_hw_start(dev); } + +static int stm32_adc_core_runtime_idle(struct device *dev) +{ + pm_runtime_mark_last_busy(dev); + + return 0; +} #endif static const struct dev_pm_ops stm32_adc_core_pm_ops = { @@ -801,7 +808,7 @@ static const struct dev_pm_ops stm32_adc_core_pm_ops = { pm_runtime_force_resume) SET_RUNTIME_PM_OPS(stm32_adc_core_runtime_suspend, stm32_adc_core_runtime_resume, - NULL) + stm32_adc_core_runtime_idle) }; static const struct stm32_adc_priv_cfg stm32f4_adc_priv_cfg = {