On Thu, Apr 02, 2020 at 01:32:35PM +0200, Nicolas Saenz Julienne wrote: > On Wed, 2020-04-01 at 15:37 -0500, Bjorn Helgaas wrote: > > On Tue, Mar 24, 2020 at 07:28:10PM +0100, Nicolas Saenz Julienne wrote: > > > On the Raspberry Pi 4, after a PCI reset, VL805's firmware may > > > either be loaded directly from an EEPROM or, if not present, by > > > the SoC's VideCore. The function informs VideCore that VL805 was > > > just reset, or requests for a probe defer. Is VL805 the XHCI USB device? A hint here would help non-RPi experts know how this fits into the topology. > > > Based on Tim Gover's downstream implementation. > > > > Maybe a URL? > > I was under the impression that adding links in the commit log that > are likely to be short-lived was frowned upon. That said I could've > added it into the cover letter. For reference here it is: > > https://github.com/raspberrypi/linux/commit/9935b4c7e360b4494b4cb6e3ce797238a1ab78bd I think your impression is correct. If this was posted to a mailing list archived on lore.kernel.org, a link to the cover letter would be ideal. > To pass messages down the mailbox, you call rpi_firmware_property(), > which takes care of contention, formating and DMA issues, before > passing it into the actual mailbox interface and beyond. OK. The "rpi_firmware_property" name doesn't give much of a hint that it is sending messages. It sounds like it might be a lookup function. But that's an existing thing, not something you're changing here. > > > + */ > > > +int rpi_firmware_init_vl805(struct pci_dev *pdev) > > > +{ > > > + struct device_node *fw_np; > > > + struct rpi_firmware *fw; > > > + u32 dev_addr; > > > + int ret; > > > + > > > + fw_np = of_find_compatible_node(NULL, NULL, > > > + "raspberrypi,bcm2835-firmware"); > > > + if (!fw_np) > > > + return 0; > > > + > > > + fw = rpi_firmware_get(fw_np); > > > + of_node_put(fw_np); > > > + if (!fw) > > > + return -EPROBE_DEFER; > > > + > > > + dev_addr = pdev->bus->number << 20 | PCI_SLOT(pdev->devfn) << 15 | > > > + PCI_FUNC(pdev->devfn) << 12; > > > + > > > + ret = rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_XHCI_RESET, > > > + &dev_addr, sizeof(dev_addr)); > > > + if (ret) > > > + return ret; > > > + > > > + dev_dbg(&pdev->dev, "loaded Raspberry Pi's VL805 firmware\n"); > > > + > > > + return 0; > > > +} > > > +EXPORT_SYMBOL_GPL(rpi_firmware_init_vl805); > > > + > > > static const struct of_device_id rpi_firmware_of_match[] = { > > > { .compatible = "raspberrypi,bcm2835-firmware", }, > > > {}, > > [...] > > Regards, > Nicolas >
