From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.smtpout.orange.fr (smtp-25.smtpout.orange.fr [80.12.242.25]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BFD437482; Mon, 8 Apr 2024 20:35:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.12.242.25 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712608518; cv=none; b=NpTWQdWqfq0pUKB5aI9cJZFOOgpUoWhNcaduRTIZJpC1d3TGbtxpKWkTc+uEVYU6QTSP0jysP9BVLDI6BQ2J7XKjPdNUR2H2sV5oeDydXN+W61ZzsCR9Z9q6zOkBdywg23I5g78lNbCmJDGF+IgZQpGTI3Xh+/HDDrOgUBtJGrU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712608518; c=relaxed/simple; bh=6wIbXijNZnjnOQq/sRLb9m1wVYCIfcRdMHTfHRaLA0s=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=SLkOaSd71aTTkUPKQGK1nsBHMmjJ1LR+uL4nbLgxX1t1+ZUlN/rfHjzoqVOK3A9yGz98cNKEODt3GwJKXcAFy0DnZ6lyvA6E6Z4P3O9LqttgYolDW3YxFOr/Mkrezpk09jibI7ED7EOrCTe35CPBKLqQ5aq1BJEso9oPr3ZVtE8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wanadoo.fr; spf=pass smtp.mailfrom=wanadoo.fr; dkim=pass (2048-bit key) header.d=wanadoo.fr header.i=@wanadoo.fr header.b=V+c/5SYg; arc=none smtp.client-ip=80.12.242.25 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wanadoo.fr Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wanadoo.fr Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=wanadoo.fr header.i=@wanadoo.fr header.b="V+c/5SYg" Received: from [192.168.1.18] ([86.243.17.157]) by smtp.orange.fr with ESMTPA id tvZIrDqpwcdQQtvZIr8sCw; Mon, 08 Apr 2024 22:26:23 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wanadoo.fr; s=t20230301; t=1712607983; bh=GgXY2ZURZjB5f6jznbBiGTWLjQntZx7NuXSDPoPAJoY=; h=Message-ID:Date:MIME-Version:From:Subject:To; b=V+c/5SYgM+nv6Z4DXzXctxKJC5zWfV353MCYZ/bLp6iRpydM5VYGzPiKynORj8fXM 6CXHzEAOfpcCrnhm35VAUnbjZwus6d9tY51DBtyVZPXG3UBBr0rpW/bGBrLsVuI/do LfZzGR7qLiJKflrTNoEdH6/KBtxlDARrpTIhp97wtnnHMDmkwDBIyDgxj2TzGImrma qoW4i/SxjRF/CLUd658+iW/GUjUXvQgdbr2/+atsRYcXmSpx5/LOhk5LtCN8Mp9yp9 ugbiL5thw9/W4WTUkMKsRqZWeAUULX6AyjR8ijnRMi6/KFCt1iQvGqmGgeDbj95jrB G7saZ67RahwAA== X-ME-Helo: [192.168.1.18] X-ME-Auth: Y2hyaXN0b3BoZS5qYWlsbGV0QHdhbmFkb28uZnI= X-ME-Date: Mon, 08 Apr 2024 22:26:23 +0200 X-ME-IP: 86.243.17.157 Message-ID: <6450334d-596b-4982-8a17-eefc8585e036@wanadoo.fr> Date: Mon, 8 Apr 2024 22:26:16 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Christophe JAILLET Subject: Re: [PATCH v1 3/4] usb: dwc3: exynos: Use devm_regulator_bulk_get_enable() helper function To: Anand Moon Cc: Thinh Nguyen , Greg Kroah-Hartman , Krzysztof Kozlowski , Alim Akhtar , linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20240301193831.3346-1-linux.amoon@gmail.com> <20240301193831.3346-4-linux.amoon@gmail.com> <52158bf6-16fe-4ce2-b9b6-bbc6550a6e14@wanadoo.fr> Content-Language: en-MW In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Le 08/04/2024 à 12:02, Anand Moon a écrit : > Hi Christophe, > > On Fri, 5 Apr 2024 at 21:42, Christophe JAILLET > wrote: >> >> Le 05/04/2024 à 08:10, Anand Moon a écrit : >>> Hi Christophe, Krzysztof, >>> >>> On Mon, 4 Mar 2024 at 17:16, Anand Moon wrote: >>>> >>>> Hi Christophe, >>>> >>>> On Sun, 3 Mar 2024 at 00:07, Christophe JAILLET >>>> wrote: >>>>> >>>>> Le 02/03/2024 à 17:48, Anand Moon a écrit : >>>>>> Hi Christophe, >>>>>> >>>>>> On Sat, 2 Mar 2024 at 21:20, Christophe JAILLET >>>>>> wrote: >>>>>>> >>>>>>> Le 01/03/2024 à 20:38, Anand Moon a écrit : >>>>>>>> Use devm_regulator_bulk_get_enable() instead of open coded >>>>>>>> 'devm_regulator_get(), regulator_enable(), regulator_disable(). >>>>>>>> >>>>>>>> Signed-off-by: Anand Moon >>>>>>>> --- >>>>>>>> drivers/usb/dwc3/dwc3-exynos.c | 49 +++------------------------------- >>>>>>>> 1 file changed, 4 insertions(+), 45 deletions(-) >>>>>>>> >>>>>>>> diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c >>>>>>>> index 5d365ca51771..7c77f3c69825 100644 >>>>>>>> --- a/drivers/usb/dwc3/dwc3-exynos.c >>>>>>>> +++ b/drivers/usb/dwc3/dwc3-exynos.c >>>>>>>> @@ -32,9 +32,6 @@ struct dwc3_exynos { >>>>>>>> struct clk *clks[DWC3_EXYNOS_MAX_CLOCKS]; >>>>>>>> int num_clks; >>>>>>>> int suspend_clk_idx; >>>>>>>> - >>>>>>>> - struct regulator *vdd33; >>>>>>>> - struct regulator *vdd10; >>>>>>>> }; >>>>>>>> >>>>>>>> static int dwc3_exynos_probe(struct platform_device *pdev) >>>>>>>> @@ -44,6 +41,7 @@ static int dwc3_exynos_probe(struct platform_device *pdev) >>>>>>>> struct device_node *node = dev->of_node; >>>>>>>> const struct dwc3_exynos_driverdata *driver_data; >>>>>>>> int i, ret; >>>>>>>> + static const char * const regulators[] = { "vdd33", "vdd10" }; >>>>>>>> >>>>>>>> exynos = devm_kzalloc(dev, sizeof(*exynos), GFP_KERNEL); >>>>>>>> if (!exynos) >>>>>>>> @@ -78,27 +76,9 @@ static int dwc3_exynos_probe(struct platform_device *pdev) >>>>>>>> if (exynos->suspend_clk_idx >= 0) >>>>>>>> clk_prepare_enable(exynos->clks[exynos->suspend_clk_idx]); >>>>>>>> >>>>>>>> - exynos->vdd33 = devm_regulator_get(dev, "vdd33"); >>>>>>>> - if (IS_ERR(exynos->vdd33)) { >>>>>>>> - ret = PTR_ERR(exynos->vdd33); >>>>>>>> - goto vdd33_err; >>>>>>>> - } >>>>>>>> - ret = regulator_enable(exynos->vdd33); >>>>>>>> - if (ret) { >>>>>>>> - dev_err(dev, "Failed to enable VDD33 supply\n"); >>>>>>>> - goto vdd33_err; >>>>>>>> - } >>>>>>>> - >>>>>>>> - exynos->vdd10 = devm_regulator_get(dev, "vdd10"); >>>>>>>> - if (IS_ERR(exynos->vdd10)) { >>>>>>>> - ret = PTR_ERR(exynos->vdd10); >>>>>>>> - goto vdd10_err; >>>>>>>> - } >>>>>>>> - ret = regulator_enable(exynos->vdd10); >>>>>>>> - if (ret) { >>>>>>>> - dev_err(dev, "Failed to enable VDD10 supply\n"); >>>>>>>> - goto vdd10_err; >>>>>>>> - } >>>>>>>> + ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(regulators), regulators); >>>>>>>> + if (ret) >>>>>>>> + return dev_err_probe(dev, ret, "Failed to enable regulators\n"); >>>>>>>> >>>>>>>> if (node) { >>>>>>>> ret = of_platform_populate(node, NULL, NULL, dev); >>>>>>>> @@ -115,10 +95,6 @@ static int dwc3_exynos_probe(struct platform_device *pdev) >>>>>>>> return 0; >>>>>>>> >>>>>>>> populate_err: >>>>>>>> - regulator_disable(exynos->vdd10); >>>>>>>> -vdd10_err: >>>>>>>> - regulator_disable(exynos->vdd33); >>>>>>>> -vdd33_err: >>>>>>>> for (i = exynos->num_clks - 1; i >= 0; i--) >>>>>>>> clk_disable_unprepare(exynos->clks[i]); >>>>>>>> >>>>>>>> @@ -140,9 +116,6 @@ static void dwc3_exynos_remove(struct platform_device *pdev) >>>>>>>> >>>>>>>> if (exynos->suspend_clk_idx >= 0) >>>>>>>> clk_disable_unprepare(exynos->clks[exynos->suspend_clk_idx]); >>>>>>>> - >>>>>>>> - regulator_disable(exynos->vdd33); >>>>>>>> - regulator_disable(exynos->vdd10); >>>>>>>> } >>>>>>>> >>>>>>>> static const struct dwc3_exynos_driverdata exynos5250_drvdata = { >>>>>>>> @@ -196,9 +169,6 @@ static int dwc3_exynos_suspend(struct device *dev) >>>>>>>> for (i = exynos->num_clks - 1; i >= 0; i--) >>>>>>>> clk_disable_unprepare(exynos->clks[i]); >>>>>>>> >>>>>>>> - regulator_disable(exynos->vdd33); >>>>>>>> - regulator_disable(exynos->vdd10); >>>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> Same here, I don't think that removing regulator_[en|dis]able from the >>>>>>> suspend and resume function is correct. >>>>>>> >>>>>>> The goal is to stop some hardware when the system is suspended, in order >>>>>>> to save some power. >>>>>> Ok, >>>>>>> >>>>>>> Why did you removed it? >>>>>> >>>>>> As per the description of the function devm_regulator_bulk_get_enable >>>>>> >>>>>> * This helper function allows drivers to get several regulator >>>>>> * consumers in one operation with management, the regulators will >>>>>> * automatically be freed when the device is unbound. If any of the >>>>>> * regulators cannot be acquired then any regulators that were >>>>>> * allocated will be freed before returning to the caller. >>>>> >>>>> The code in suspend/resume is not about freeing some resources. It is >>>>> about enabling/disabling some hardware to save some power. >>>>> >>>>> Think to the probe/remove functions as the software in the kernel that >>>>> knows how to handle some hardawre, and the suspend/resume as the on/off >>>>> button to power-on and off the electrical chips. >>>>> >>>>> When the system is suspended, the software is still around. But some >>>>> hardware can be set in a low consumption mode to save some power. >>>>> >>>>> IMHO, part of the code you removed changed this behaviour and increase >>>>> the power consumption when the system is suspended. >>>>> >>>> >>>> You are correct, I have changed the regulator API from >>>> devm_regulator_get_enable to devm_regulator_bulk_get_enable >>>> which changes this behavior. >>>> I will fix it in the next version. >>>> >>>>> CJ >>> >>> I could not find any example in the kernel to support >>> devm_regulator_bulk_disable >>> but here is my modified file. >>> >>> If you have any suggestions for this plz let me know. >> >> I don't think that your approach is correct, and I don't think that the >> proposed patch does what you expect it to do. >> >> Calling a devm_ function in suspend/resume functions looks really >> strange to me and is likely broken. >> >> Especially here, devm_regulator_bulk_get_enable() in the resume function >> allocates some memory that is not freed in >> devm_regulator_bulk_disable(), because the API is not designed to work >> like that. So this could generate a kind of memory leak. >> >> >> *I think that the code is good enough as-is*, but if you really want to >> change something, maybe: >> - devm_regulator_get()+regulator_enable() in the probe could be >> changed to devm_regulator_get_enable() >> - the resume/suspend function should be left as-is with >> regulator_disable()/regulator_ensable() >> - remove regulator_disable() from the error handling path of the >> probe and from the remove function. >> >> I *think* it would work. >> > No devm_regulator_get_enable use the same logic as > devm_regulator_bulk_get_enable > to enable the regulator. Yes, the logic is the same, but you get a pointer to the "struct regulator" which can be used to disable/enable in the suspend/resume functions. With the bulk version, you can not do that. See my first reply on your 3/4 patch. > > [0] https://elixir.bootlin.com/linux/latest/source/drivers/regulator/devres.c#L126 > > So as of now I am dropping the changes on the regulator in this patch series. I do agree that it is certainly the way to go here. CJ > >> CJ >> > Thanks for your inputs. > > Thanks > > -Anand > >