-----Original Message-----
From: Lorenzo Pieralisi <redacted>
Sent: Thursday, December 23, 2021 7:50 PM
To: Hongxing Zhu <hongxing.zhu@nxp.com>
Cc: Krzysztof Wilczyński <redacted>; l.stach@pengutronix.de;
bhelgaas@google.com; Marcel Ziswiler [off-list ref];
tharvey@gateworks.com; kishon@ti.com; vkoul@kernel.org;
robh@kernel.org; galak@kernel.crashing.org; shawnguo@kernel.org;
linux-phy@lists.infradead.org; devicetree@vger.kernel.org;
linux-pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
linux-kernel@vger.kernel.org; kernel@pengutronix.de; dl-linux-imx
[off-list ref]
Subject: Re: [PATCH v7 8/8] PCI: imx: Add the imx8mm pcie support

On Fri, Dec 17, 2021 at 05:54:21AM +0000, Hongxing Zhu wrote:

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-----Original Message-----
From: Krzysztof Wilczyński <redacted>
Sent: Friday, December 17, 2021 12:52 AM
To: Hongxing Zhu <hongxing.zhu@nxp.com>
Cc: l.stach@pengutronix.de; bhelgaas@google.com;
lorenzo.pieralisi@arm.com; Marcel Ziswiler
[off-list ref]; tharvey@gateworks.com;

kishon@ti.com;

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vkoul@kernel.org; robh@kernel.org; galak@kernel.crashing.org;
shawnguo@kernel.org; linux-phy@lists.infradead.org;
devicetree@vger.kernel.org; linux-pci@vger.kernel.org;
linux-arm-kernel@lists.infradead.org;
linux-kernel@vger.kernel.org; kernel@pengutronix.de; dl-linux-imx
[off-list ref]
Subject: Re: [PATCH v7 8/8] PCI: imx: Add the imx8mm pcie support

Hi Richard,

Apologies for a very late review!  Especially since Lorenzo already
took patches as per:

https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flo

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r

e.kernel.org%2Flinux-pci%2F163965080404.20006.52416095516435017

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49.b4-ty%40arm.com%2F&data=04%7C01%7Chongxing.zhu%40nxp

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.com%7C8afb673348214261883608d9c0b45b1d%7C686ea1d3bc2b4

c6fa

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92cd99c5c301635%7C0%7C0%7C637752703124166805%7CUnknown%7

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CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1ha

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WwiLCJXVCI6Mn0%3D%7C3000&sdata=rfmN1Xojubap2vi3J4Jol3ozy

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N1Q2q7YiBM5bqMm22s%3D&reserved=0

However, perhaps it's not too late.

[Richard Zhu] Hi Krzysztof:
Thanks for your review.
But I don't know how to handle this situation.
How about that I add this refine patch into the following bug fix and
refine patch-set later?
PCI: imx6: refine codes and add compliance tests mode support "

https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpa
tchwork.kernel.org%2Fproject%2Flinux-arm-kernel%2Fcover%2F1635747
478-25562-1-git-send-email-hongxing.zhu%40nxp.com%2F&data=0
4%7C01%7Chongxing.zhu%40nxp.com%7Ce04c6cda020b4f3849bf08d9c
60a5da0%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C1%7C6377
58570100053598%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwM
DAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&
sdata=joTJZcYJhmYlzSTWY%2BhGCFV5ch12HPR4mbbOwZ5vcO0%3D&a
mp;reserved=0"

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[...]

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@@ -446,6 +452,13 @@ static int imx6_pcie_enable_ref_clk(struct

imx6_pcie *imx6_pcie)

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 		break;
 	case IMX7D:
 		break;
+	case IMX8MM:
+		ret = clk_prepare_enable(imx6_pcie->pcie_aux);
+		if (ret) {
+			dev_err(dev, "unable to enable pcie_aux clock\n");
+			break;
+		}
+		break;

You can drop the inner break, it wouldn't do much here, unless this
was intended to be a return?

[Richard Zhu] Yes, it is. The inner break can be dropped. The error
return would be handled in the end.

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@@ -538,6 +559,10 @@ static void

imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)

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 	case IMX8MQ:
 		reset_control_deassert(imx6_pcie->pciephy_reset);
 		break;
+	case IMX8MM:
+		if (phy_init(imx6_pcie->phy) != 0)
+			dev_err(dev, "Waiting for PHY ready timeout!\n");
+		break;

If the above, you can keep the same style as used throughout the
file already, so it would just simply be:

  if (phy_init(imx6_pcie->phy))

Also, a nitpick: to be consistent with other such messages here, the
error message would be all lower-case letters.

[Richard Zhu] Yes, it is.

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[...]

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@@ -614,6 +639,8 @@ static void imx6_pcie_configure_type(struct

imx6_pcie *imx6_pcie)  static void imx6_pcie_init_phy(struct

imx6_pcie

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*imx6_pcie)  {
 	switch (imx6_pcie->drvdata->variant) {
+	case IMX8MM:
+		break;
 	case IMX8MQ:

Would it warrant a comment that adds a note there to this single
bare break?  Perhaps this version is not support, lack this
particular functionality, etc.

[Richard Zhu] Yes, it's easier to understand after add one comment.

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[...]

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@@ -1089,10 +1122,39 @@ static int imx6_pcie_probe(struct

platform_device *pdev)

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 			dev_err(dev, "Failed to get PCIE APPS reset

control\n");

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 			return PTR_ERR(imx6_pcie->apps_reset);
 		}
+		break;
+	case IMX8MM:
+		imx6_pcie->pcie_aux = devm_clk_get(dev, "pcie_aux");
+		if (IS_ERR(imx6_pcie->pcie_aux))
+			return dev_err_probe(dev,

PTR_ERR(imx6_pcie->pcie_aux),

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+					     "pcie_aux clock source missing or

invalid\n");

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+		imx6_pcie->apps_reset =

devm_reset_control_get_exclusive(dev,

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+									 "apps");
+		if (IS_ERR(imx6_pcie->apps_reset)) {
+			dev_err(dev, "Failed to get PCIE APPS reset

control\n");

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+			return PTR_ERR(imx6_pcie->apps_reset);
+		}
+
+		imx6_pcie->phy = devm_phy_get(dev, "pcie-phy");
+		if (IS_ERR(imx6_pcie->phy)) {
+			if (PTR_ERR(imx6_pcie->phy) == -EPROBE_DEFER)
+				return -EPROBE_DEFER;
+			dev_err(dev, "Failed to get PCIE PHY\n");
+			return PTR_ERR(imx6_pcie->phy);
+		}

A question about handling of the -EPROBE_DEFER above: why not to

use

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the
dev_err_probe() helper similarly to the code above and below?

Would

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there be something different preventing the use of dev_err_probe()
here too?

[Richard Zhu] To be aligned, the above one can be replaced totally.
I didn't want to dump the error message when -EPROBE_DEFFER

occurs.

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Anyway, I can make them aligned later.

Can you send me an update for this patch only so that I can update the
corresponding commit according to this review please ?

[Richard Zhu] Sure, thanks a lot for your kindly help.

Best Regards
Richard Zhu

Thanks,
Lorenzo

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Best Regards
Richard

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 		break;
 	default:
 		break;
 	}
+	/* Don't fetch the pcie_phy clock, if it has abstract PHY driver */
+	if (imx6_pcie->phy == NULL) {
+		imx6_pcie->pcie_phy = devm_clk_get(dev, "pcie_phy");
+		if (IS_ERR(imx6_pcie->pcie_phy))
+			return dev_err_probe(dev,

PTR_ERR(imx6_pcie->pcie_phy),

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+					     "pcie_phy clock source missing or

invalid\n");

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+	}

Thank you for another amazing patch!

	Krzysztof

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