From: Lucas Stach <l.stach@pengutronix.de>
To: Richard Zhu <hongxing.zhu@nxp.com>,
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
Subject: Re: [PATCH v2] PCI: imx6: Assert i.MX8MM CLKREQ# even if no device present
Date: Wed, 16 Mar 2022 10:29:29 +0100 [thread overview]
Message-ID: <2e4f1fa1add244b12954970b3c02cbe503176a26.camel@pengutronix.de> (raw)
In-Reply-To: <1645672013-8949-1-git-send-email-hongxing.zhu@nxp.com>
Am Donnerstag, dem 24.02.2022 um 11:06 +0800 schrieb Richard Zhu:
> 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>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> 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) {
next prev parent reply other threads:[~2022-03-16 9:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
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 9:29 ` Lucas Stach [this message]
2022-03-17 9:01 ` Lorenzo Pieralisi
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