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From:   Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
To:     linux-kernel@vger.kernel.org,
        Florian Fainelli <f.fainelli@gmail.com>,
        bcm-kernel-feedback-list@broadcom.com,
        Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Andrew Murray <amurray@thegoodpenguin.co.uk>
Cc:     linux-usb@vger.kernel.org, linux-rpi-kernel@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, gregkh@linuxfoundation.org,
        tim.gover@raspberrypi.org, linux-pci@vger.kernel.org,
        wahrenst@gmx.net, Bjorn Helgaas <bhelgaas@google.com>
Subject: [PATCH v4 3/4] PCI: brcmstb: Wait for Raspberry Pi's firmware when present
Date:   Fri,  6 Mar 2020 12:43:47 +0100
Message-Id: <20200306114348.5172-4-nsaenzjulienne@suse.de>
In-Reply-To: <20200306114348.5172-1-nsaenzjulienne@suse.de>
References: <20200306114348.5172-1-nsaenzjulienne@suse.de>
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xHCI's PCI fixup, run at the end of pcie-brcmstb's probe, depends on
RPi4's VideoCore firmware interface to be up and running. It's possible
for both initializations to race, so make sure it's available prior
starting.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/pci/controller/pcie-brcmstb.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 3a10e678c7f4..a3d3070a5832 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -28,6 +28,8 @@
 #include <linux/string.h>
 #include <linux/types.h>
 
+#include <soc/bcm2835/raspberrypi-firmware.h>
+
 #include "../pci.h"
 
 /* BRCM_PCIE_CAP_REGS - Offset for the mandatory capability config regs */
@@ -917,11 +919,24 @@ static int brcm_pcie_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node, *msi_np;
 	struct pci_host_bridge *bridge;
+	struct device_node *fw_np;
 	struct brcm_pcie *pcie;
 	struct pci_bus *child;
 	struct resource *res;
 	int ret;
 
+	/*
+	 * We have to wait for the Raspberry Pi's firmware interface to be up
+	 * as some PCI fixups depend on it.
+	 */
+	fw_np = of_find_compatible_node(NULL, NULL,
+					"raspberrypi,bcm2835-firmware");
+	if (fw_np && !rpi_firmware_get(fw_np)) {
+		of_node_put(fw_np);
+		return -EPROBE_DEFER;
+	}
+	of_node_put(fw_np);
+
 	bridge = devm_pci_alloc_host_bridge(&pdev->dev, sizeof(*pcie));
 	if (!bridge)
 		return -ENOMEM;
-- 
2.25.1