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From: Richard Zhu <hongxing.zhu@nxp.com>
To: l.stach@pengutronix.de, bhelgaas@google.com, lorenzo.pieralisi@arm.com
Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, kernel@pengutronix.de,
	linux-imx@nxp.com, Richard Zhu <hongxing.zhu@nxp.com>
Subject: [PATCH v2] PCI: imx6: Assert i.MX8MM CLKREQ# even if no device present
Date: Thu, 24 Feb 2022 11:06:53 +0800	[thread overview]
Message-ID: <1645672013-8949-1-git-send-email-hongxing.zhu@nxp.com> (raw)

The CLKREQ# signal is an open drain, active low signal that is driven
low by the remote Endpoint device. But it might not be driven low if no
Endpoint device is connected.

On i.MX8MM PCIe, phy_init() may fail and system boot may hang if no
Endpoint is connected to assert CLKREQ#.

Handle this as on i.MX8MQ, where we explicitly assert CLKREQ# so the
PHY can be initialized.

Fixes: 178e244cb6e2 ("PCI: imx: Add the imx8mm pcie support")
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
 drivers/pci/controller/dwc/pci-imx6.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 78e32a539060..168cb1287ba9 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -447,10 +447,6 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
 	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;
 	case IMX8MQ:
 		ret = clk_prepare_enable(imx6_pcie->pcie_aux);
 		if (ret) {
-- 
2.25.1


WARNING: multiple messages have this Message-ID (diff)
From: Richard Zhu <hongxing.zhu@nxp.com>
To: l.stach@pengutronix.de, bhelgaas@google.com, lorenzo.pieralisi@arm.com
Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, kernel@pengutronix.de,
	linux-imx@nxp.com, Richard Zhu <hongxing.zhu@nxp.com>
Subject: [PATCH v2] PCI: imx6: Assert i.MX8MM CLKREQ# even if no device present
Date: Thu, 24 Feb 2022 11:06:53 +0800	[thread overview]
Message-ID: <1645672013-8949-1-git-send-email-hongxing.zhu@nxp.com> (raw)

The CLKREQ# signal is an open drain, active low signal that is driven
low by the remote Endpoint device. But it might not be driven low if no
Endpoint device is connected.

On i.MX8MM PCIe, phy_init() may fail and system boot may hang if no
Endpoint is connected to assert CLKREQ#.

Handle this as on i.MX8MQ, where we explicitly assert CLKREQ# so the
PHY can be initialized.

Fixes: 178e244cb6e2 ("PCI: imx: Add the imx8mm pcie support")
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
 drivers/pci/controller/dwc/pci-imx6.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 78e32a539060..168cb1287ba9 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -447,10 +447,6 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
 	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;
 	case IMX8MQ:
 		ret = clk_prepare_enable(imx6_pcie->pcie_aux);
 		if (ret) {
-- 
2.25.1


_______________________________________________
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             reply	other threads:[~2022-02-24  3:15 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-24  3:06 Richard Zhu [this message]
2022-02-24  3:06 ` [PATCH v2] PCI: imx6: Assert i.MX8MM CLKREQ# even if no device present Richard Zhu
2022-03-16  0:13 ` Hongxing Zhu
2022-03-16  0:13   ` Hongxing Zhu
2022-03-16  9:29 ` Lucas Stach
2022-03-16  9:29   ` Lucas Stach
2022-03-17  9:01 ` Lorenzo Pieralisi
2022-03-17  9:01   ` Lorenzo Pieralisi

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