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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id E842FC77B73 for ; Mon, 5 Jun 2023 07:15:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Z7CzaTADA1SqnvuuVuGSglne9tHg3mro073dY7ZW52M=; b=bEnjrqXufIB00H MPnFSWqc2XPh7P6CKtSbg2spCB0EJow9GU9az9qtfl009QeSbmiFOPLdSiCfvnBABrIk06uEl8Msw 8+2znYU1yY+Dq8k9Zggd+Jp2P+Lk+gf6utd2PNdp0c21wxSxcYeYq7pC7lrQkCYK1Qe/78KRsN4mN hR/LpyqUMAbMePV5BdKq1v5wDiYeIPL3AUNg6Vj/CXospFP62mc9hPo2MGju/FjYEL/KxkdZvzHuF DOe+hBNI4uYnjtsWMDc/pMOT75N8uPGppwL0Vcqv79DfHKeVxpDDPDw6eaoukaev20m7CXA2BSzg1 q+ci0vTIt44s+5UYajrQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q64RA-00EWKS-0U; Mon, 05 Jun 2023 07:15:32 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1q64R7-00EWJR-0t for linux-arm-kernel@lists.infradead.org; Mon, 05 Jun 2023 07:15:31 +0000 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 1q64Qz-0001Vy-Ev; Mon, 05 Jun 2023 09:15:21 +0200 Received: from mfe by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1q64Qy-0007Wj-O6; Mon, 05 Jun 2023 09:15:20 +0200 Date: Mon, 5 Jun 2023 09:15:20 +0200 From: Marco Felsch To: Lucas Stach Cc: Shawn Guo , Marek Vasut , Luca Ceresoli , patchwork-lst@pengutronix.de, NXP Linux Team , Pengutronix Kernel Team , Fabio Estevam , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 2/2] soc: imx: gpcv2: prepare bus clocks early Message-ID: <20230605071520.xjo3kcc7cmpheqwn@pengutronix.de> References: <20230602185417.4098937-1-l.stach@pengutronix.de> <20230602185417.4098937-2-l.stach@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230602185417.4098937-2-l.stach@pengutronix.de> User-Agent: NeoMutt/20180716 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: mfe@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230605_001529_627846_8FC6843C X-CRM114-Status: GOOD ( 25.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Lucas, thanks for posting. On 23-06-02, Lucas Stach wrote: > Prepare the bus clocks during PGC domain driver probe. This avoids a > potential deadlock when there a clock providers inside the domain, > as this might end up trying to take the CCF prepare_lock from two > different contexts, when runtime PM is trying to resume the PGC domain > for the clock provider. By keeping the bus clocks prepared as long as > there is a PGC domain driver attached, we don't need to take the > prepare_lock in the domain power up/down paths. > > We don't want to do this for regular reset clocks, as this might lead > to some PLLs being kept prepared that could otherwise be shut down. > For the bus clocks this isn't a concern, as all the bus clocks are > derived from always-on system PLLs. > > Signed-off-by: Lucas Stach Feel free to add my rb for both patches. Reviewed-by: Marco Felsch > --- > drivers/soc/imx/gpcv2.c | 41 ++++++++++++++++++++++++++++++++++------- > 1 file changed, 34 insertions(+), 7 deletions(-) > > diff --git a/drivers/soc/imx/gpcv2.c b/drivers/soc/imx/gpcv2.c > index 706f852e5d87..428e2fd82f26 100644 > --- a/drivers/soc/imx/gpcv2.c > +++ b/drivers/soc/imx/gpcv2.c > @@ -337,10 +337,14 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd) > > reset_control_assert(domain->reset); > > - /* Enable reset clocks for all devices in the domain */ > - ret = clk_bulk_prepare_enable(domain->num_clks, domain->clks); > + if (!domain->bus_clocks) > + /* Enable reset clocks for all devices in the domain */ > + ret = clk_bulk_prepare_enable(domain->num_clks, domain->clks); > + else > + /* Enable bus clocks for this domain */ > + ret = clk_bulk_enable(domain->num_clks, domain->clks); > if (ret) { > - dev_err(domain->dev, "failed to enable reset clocks\n"); > + dev_err(domain->dev, "failed to enable clocks\n"); > goto out_regulator_disable; > } > > @@ -402,7 +406,10 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd) > return 0; > > out_clk_disable: > - clk_bulk_disable_unprepare(domain->num_clks, domain->clks); > + if (!domain->bus_clocks) > + clk_bulk_disable_unprepare(domain->num_clks, domain->clks); > + else > + clk_bulk_disable(domain->num_clks, domain->clks); > out_regulator_disable: > if (!IS_ERR(domain->regulator)) > regulator_disable(domain->regulator); > @@ -466,8 +473,11 @@ static int imx_pgc_power_down(struct generic_pm_domain *genpd) > } > } > > - /* Disable reset clocks for all devices in the domain */ > - clk_bulk_disable_unprepare(domain->num_clks, domain->clks); > + /* Disable bus or reset clocks for all devices in the domain */ > + if (!domain->bus_clocks) > + clk_bulk_disable_unprepare(domain->num_clks, domain->clks); > + else > + clk_bulk_disable(domain->num_clks, domain->clks); > > if (!IS_ERR(domain->regulator)) { > ret = regulator_disable(domain->regulator); > @@ -486,6 +496,8 @@ static int imx_pgc_power_down(struct generic_pm_domain *genpd) > out_clk_disable: > if (!domain->bus_clocks) > clk_bulk_disable_unprepare(domain->num_clks, domain->clks); > + else > + clk_bulk_disable(domain->num_clks, domain->clks); > > return ret; > } > @@ -1343,10 +1355,19 @@ static int imx_pgc_domain_probe(struct platform_device *pdev) > regmap_update_bits(domain->regmap, domain->regs->map, > domain->bits.map, domain->bits.map); > > + if (domain->bus_clocks) { > + ret = clk_bulk_prepare(domain->num_clks, domain->clks); > + if (ret) { > + dev_err(domain->dev, > + "Failed to prepare domain's clocks\n"); > + goto out_domain_unmap; > + } > + } > + > ret = pm_genpd_init(&domain->genpd, NULL, true); > if (ret) { > dev_err(domain->dev, "Failed to init power domain\n"); > - goto out_domain_unmap; > + goto out_disable_clocks; > } > > if (IS_ENABLED(CONFIG_LOCKDEP) && > @@ -1364,6 +1385,9 @@ static int imx_pgc_domain_probe(struct platform_device *pdev) > > out_genpd_remove: > pm_genpd_remove(&domain->genpd); > +out_disable_clocks: > + if (domain->bus_clocks) > + clk_bulk_unprepare(domain->num_clks, domain->clks); > out_domain_unmap: > if (domain->bits.map) > regmap_update_bits(domain->regmap, domain->regs->map, > @@ -1380,6 +1404,9 @@ static int imx_pgc_domain_remove(struct platform_device *pdev) > of_genpd_del_provider(domain->dev->of_node); > pm_genpd_remove(&domain->genpd); > > + if (domain->bus_clocks) > + clk_bulk_unprepare(domain->num_clks, domain->clks); > + > if (domain->bits.map) > regmap_update_bits(domain->regmap, domain->regs->map, > domain->bits.map, 0); > -- > 2.39.2 > > > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel