[PATCH v8 3/4] PCI: brcmstb: Wait for Raspberry Pi's firmware when present
From: Nicolas Saenz Julienne <hidden>
Date: 2020-05-05 16:13:34
Also in:
linux-pci, linux-usb, lkml
Subsystem:
broadcom bcm2711/bcm2835 arm architecture, broadcom bcm7xxx arm architecture, broadcom stb pcie driver, pci native host bridge and endpoint drivers, pci subsystem, the rest · Maintainers:
Florian Fainelli, Jim Quinlan, Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds
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 to starting. Signed-off-by: Nicolas Saenz Julienne <redacted> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> --- Changes since v6: - Add more complete comment drivers/pci/controller/pcie-brcmstb.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 6d79d14527a6..0b97b94c4a9a 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 +919,26 @@ 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 Raspberry Pi's firmware interface to be up as a + * PCI fixup, rpi_firmware_init_vl805(), depends on it. This driver's + * probe can race with the firmware interface's (see + * drivers/firmware/raspberrypi.c) and potentially break the PCI fixup. + */ + 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;
--
2.26.2
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