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[73.19.0.61]) by smtp.gmail.com with ESMTPSA id e16sm8238865pfb.102.2017.03.28.08.43.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Mar 2017 08:43:05 -0700 (PDT) From: Andrey Smirnov To: Bjorn Helgaas Cc: Andrey Smirnov , yurovsky@gmail.com, Lucas Stach , Fabio Estevam , Dong Aisheng , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v8 2/4] PCI: imx6: Allow probe deferal by reset GPIO Date: Tue, 28 Mar 2017 08:42:50 -0700 Message-Id: <20170328154252.6902-3-andrew.smirnov@gmail.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170328154252.6902-1-andrew.smirnov@gmail.com> References: <20170328154252.6902-1-andrew.smirnov@gmail.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Some designs implement reset GPIO via a GPIO expander connected to a peripheral bus. One such example would be i.MX7 Sabre board where said GPIO is provided by SPI shift register connected to a bitbanged SPI bus. In order to support such designs allow reset GPIO request to defer probing of the driver. Cc: yurovsky@gmail.com Cc: Lucas Stach Cc: Fabio Estevam Cc: Dong Aisheng Cc: linux-pci@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Lucas Stach Signed-off-by: Andrey Smirnov --- drivers/pci/dwc/pci-imx6.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c index e0c36d6..64de9bb 100644 --- a/drivers/pci/dwc/pci-imx6.c +++ b/drivers/pci/dwc/pci-imx6.c @@ -595,8 +595,8 @@ static struct dw_pcie_host_ops imx6_pcie_host_ops = { .host_init = imx6_pcie_host_init, }; -static int __init imx6_add_pcie_port(struct imx6_pcie *imx6_pcie, - struct platform_device *pdev) +static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie, + struct platform_device *pdev) { struct dw_pcie *pci = imx6_pcie->pci; struct pcie_port *pp = &pci->pp; @@ -636,7 +636,7 @@ static const struct dw_pcie_ops dw_pcie_ops = { .link_up = imx6_pcie_link_up, }; -static int __init imx6_pcie_probe(struct platform_device *pdev) +static int imx6_pcie_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct dw_pcie *pci; @@ -660,10 +660,6 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) imx6_pcie->variant = (enum imx6_pcie_variants)of_device_get_match_data(dev); - /* Added for PCI abort handling */ - hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0, - "imprecise external abort"); - dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0); pci->dbi_base = devm_ioremap_resource(dev, dbi_base); if (IS_ERR(pci->dbi_base)) @@ -683,6 +679,8 @@ static int __init imx6_pcie_probe(struct platform_device *pdev) dev_err(dev, "unable to get reset gpio\n"); return ret; } + } else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) { + return imx6_pcie->reset_gpio; } /* Fetch clocks */ @@ -796,11 +794,22 @@ static struct platform_driver imx6_pcie_driver = { .name = "imx6q-pcie", .of_match_table = imx6_pcie_of_match, }, + .probe = imx6_pcie_probe, .shutdown = imx6_pcie_shutdown, }; static int __init imx6_pcie_init(void) { - return platform_driver_probe(&imx6_pcie_driver, imx6_pcie_probe); + /* + * Since probe() can be deferred we need to make sure that + * hook_fault_code is not called after __init memory is freed + * by kernel and since imx6q_pcie_abort_handler() is a no-op + * we can install the handler here without risking it + * accessing some unitialized driver state + */ + hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0, + "imprecise external abort"); + + return platform_driver_register(&imx6_pcie_driver); } device_initcall(imx6_pcie_init);