From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F84F1F955 for ; Tue, 1 Aug 2023 09:25:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2760C433C7; Tue, 1 Aug 2023 09:25:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690881931; bh=8XYO5Fs3XGCJan3ht12nOXKFKl4/FYRTCY3Bo75DSgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WTqO14xAljawvRQrUkY37wcXVFrcOZ6fWUSSRH3QnjLtCvmgjwKvcktWGzpRrhlQB B1Y3U0VfOqF36uMGrKhWktdmWBOxTY6Q4AV6h+64zkyBorT4V8+G8hlaJRB93COyXA k8moVfDjAp1pM57U12HETAAr6Evt0J22m+tEf1Tw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Adrien Thierry , Vinod Koul , Sasha Levin Subject: [PATCH 5.15 051/155] phy: qcom-snps-femto-v2: keep cfg_ahb_clk enabled during runtime suspend Date: Tue, 1 Aug 2023 11:19:23 +0200 Message-ID: <20230801091912.007023584@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230801091910.165050260@linuxfoundation.org> References: <20230801091910.165050260@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Adrien Thierry [ Upstream commit 45d89a344eb46db9dce851c28e14f5e3c635c251 ] In the dwc3 core, both system and runtime suspend end up calling dwc3_suspend_common(). From there, what happens for the PHYs depends on the USB mode and whether the controller is entering system or runtime suspend. HOST mode: (1) system suspend on a non-wakeup-capable controller The [1] if branch is taken. dwc3_core_exit() is called, which ends up calling phy_power_off() and phy_exit(). Those two functions decrease the PM runtime count at some point, so they will trigger the PHY runtime sleep (assuming the count is right). (2) runtime suspend / system suspend on a wakeup-capable controller The [1] branch is not taken. dwc3_suspend_common() calls phy_pm_runtime_put_sync(). Assuming the ref count is right, the PHY runtime suspend op is called. DEVICE mode: dwc3_core_exit() is called on both runtime and system sleep unless the controller is already runtime suspended. OTG mode: (1) system suspend : dwc3_core_exit() is called (2) runtime suspend : do nothing In host mode, the code seems to make a distinction between 1) runtime sleep / system sleep for wakeup-capable controller, and 2) system sleep for non-wakeup-capable controller, where phy_power_off() and phy_exit() are only called for the latter. This suggests the PHY is not supposed to be in a fully powered-off state for runtime sleep and system sleep for wakeup-capable controller. Moreover, downstream, cfg_ahb_clk only gets disabled for system suspend. The clocks are disabled by phy->set_suspend() [2] which is only called in the system sleep path through dwc3_core_exit() [3]. With that in mind, don't disable the clocks during the femto PHY runtime suspend callback. The clocks will only be disabled during system suspend for non-wakeup-capable controllers, through dwc3_core_exit(). [1] https://elixir.bootlin.com/linux/v6.4/source/drivers/usb/dwc3/core.c#L1988 [2] https://git.codelinaro.org/clo/la/kernel/msm-5.4/-/blob/LV.AU.1.2.1.r2-05300-gen3meta.0/drivers/usb/phy/phy-msm-snps-hs.c#L524 [3] https://git.codelinaro.org/clo/la/kernel/msm-5.4/-/blob/LV.AU.1.2.1.r2-05300-gen3meta.0/drivers/usb/dwc3/core.c#L1915 Signed-off-by: Adrien Thierry Link: https://lore.kernel.org/r/20230629144542.14906-2-athierry@redhat.com Signed-off-by: Vinod Koul Stable-dep-of: 8a0eb8f9b9a0 ("phy: qcom-snps-femto-v2: properly enable ref clock") Signed-off-by: Sasha Levin --- drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c index 136b45903c798..dfe5f09449100 100644 --- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c +++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c @@ -122,22 +122,13 @@ static int qcom_snps_hsphy_suspend(struct qcom_snps_hsphy *hsphy) 0, USB2_AUTO_RESUME); } - clk_disable_unprepare(hsphy->cfg_ahb_clk); return 0; } static int qcom_snps_hsphy_resume(struct qcom_snps_hsphy *hsphy) { - int ret; - dev_dbg(&hsphy->phy->dev, "Resume QCOM SNPS PHY, mode\n"); - ret = clk_prepare_enable(hsphy->cfg_ahb_clk); - if (ret) { - dev_err(&hsphy->phy->dev, "failed to enable cfg ahb clock\n"); - return ret; - } - return 0; } -- 2.39.2