Re: [PATCH v2 2/2] drm/glanda: Add initial DRM driver for GlandaGPU

On Thu, Jul 30, 2026 at 07:36:42PM +0200, Leander Kieweg wrote:
> +		if (ret) {
> +			drm_err(&gdev->drm, "Failed to request IRQ %d\n",
> +				gdev->irq);
> +			return ret;
> +		}
> +
> +		writel(INT_DONE, gdev->mmio_base + REG_IER);
> +		drm_info(&gdev->drm, "IRQ %d requested and enabled\n", gdev->irq);

Please drop

> +	} else {
> +		drm_warn(&gdev->drm, "No IRQ found, falling back to polling\n");
> +	}
> +
> +	ret = drm_dev_register(&gdev->drm, 0);
> +	if (ret)
> +		return ret;
> +
> +	drm_info(&gdev->drm, "GlandaGPU DRM Initialized (/dev/dri/cardX created)\n");

Please drop all such messages.

> +	return 0;
> +}
> +
> +/* Shared teardown, mirrors glanda_drm_init() */
> +static void glanda_drm_fini(struct glanda_device *gdev)
> +{
> +	drm_dev_unplug(&gdev->drm);
> +	drm_atomic_helper_shutdown(&gdev->drm);
> +
> +	/* Disable interrupts */
> +	writel(0, gdev->mmio_base + REG_IER);
> +
> +	drm_info(&gdev->drm, "GlandaGPU DRM Driver removed\n");

Ditto

> +}
> +
> +static int glandagpu_probe(struct platform_device *pdev)
> +{
> +	struct resource *res;
> +	struct glanda_device *gdev;
> +	int irq;
> +
> +	dev_info(&pdev->dev, "GlandaGPU Probe started\n");

Ditto, Driver should be silent on success.

> +
> +	gdev = devm_drm_dev_alloc(&pdev->dev, &glanda_drm_driver, struct glanda_device, drm);
> +	if (IS_ERR(gdev))
> +		return PTR_ERR(gdev);
> +
> +	platform_set_drvdata(pdev, gdev);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return -ENODEV;
> +
> +	gdev->vram_phys = res->start;
> +	gdev->vram_base = devm_ioremap(&pdev->dev, res->start, GLANDA_VRAM_SIZE);
> +	gdev->mmio_base = devm_ioremap(&pdev->dev, res->start + GLANDA_MMIO_OFFSET,
> +				       GLANDA_MMIO_SIZE);
> +	if (!gdev->vram_base || !gdev->mmio_base) {
> +		drm_err(&gdev->drm, "failed to ioremap\n");
> +		return -ENOMEM;
> +	}
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq == -ENXIO)
> +		irq = -1;	/* no IRQ resource, fall back to polling */
> +	else if (irq < 0)
> +		return irq;
> +
> +	return glanda_drm_init(gdev, irq);
> +}
> +
> +static void glandagpu_remove(struct platform_device *pdev)
> +{
> +	glanda_drm_fini(platform_get_drvdata(pdev));
> +}
> +
> +/* Device Tree match table. */
> +static const struct of_device_id glanda_of_match[] = {
> +	{ .compatible = "glanda,gpu-1.0" },
> +	{ /* end of table */  }

Drop comment, obvious.

> +};
> +
> +MODULE_DEVICE_TABLE(of, glanda_of_match);
> +
> +static struct platform_driver glandagpu_driver = {
> +	.driver = {
> +		.name = "glandagpu",
> +	   .of_match_table = glanda_of_match,

Messed indent.

> +	},
> +	.probe = glandagpu_probe,
> +	.remove = glandagpu_remove,
> +};
> +
> +/* PCI probe path for the QEMU test device, real hardware uses platform_driver */
> +static int glandagpu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> +{
> +	struct glanda_device *gdev;
> +	int ret;
> +
> +	dev_info(&pdev->dev, "GlandaGPU PCI Probe started\n");

Drop. Driver should be silent on success.

> +
> +	ret = pcim_enable_device(pdev);
> +	if (ret)
> +		return ret;
> +	pci_set_master(pdev);
> +
> +	ret = pcim_iomap_regions(pdev, BIT(0) | BIT(1), "glandagpu");
> +	if (ret)
> +		return ret;
> +
> +	gdev = devm_drm_dev_alloc(&pdev->dev, &glanda_drm_driver, struct glanda_device, drm);
> +	if (IS_ERR(gdev))
> +		return PTR_ERR(gdev);
> +
> +	pci_set_drvdata(pdev, gdev);
> +
> +	gdev->mmio_base = pcim_iomap_table(pdev)[0];
> +	gdev->vram_base = pcim_iomap_table(pdev)[1];
> +	gdev->vram_phys = pci_resource_start(pdev, 1);
> +
> +	return glanda_drm_init(gdev, pdev->irq);
> +}
> +
> +static void glandagpu_pci_remove(struct pci_dev *pdev)
> +{
> +	glanda_drm_fini(pci_get_drvdata(pdev));
> +}
> +
> +static const struct pci_device_id glanda_pci_ids[] = {
> +	{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_DEVICE_ID_GLANDA_GPU) },
> +	{ /* end of table */ }
> +};
> +
> +MODULE_DEVICE_TABLE(pci, glanda_pci_ids);
> +
> +static struct pci_driver glandagpu_pci_driver = {
> +	.name = "glandagpu-pci",
> +	.id_table = glanda_pci_ids,
> +	.probe = glandagpu_pci_probe,
> +	.remove = glandagpu_pci_remove,
> +};
> +
> +static int __init glandagpu_init(void)
> +{
> +	int ret;
> +
> +	ret = platform_driver_register(&glandagpu_driver);
> +	if (ret) {
> +		pr_err("GlandaGPU: Failed to register platform driver\n");
> +		return ret;
> +	}
> +
> +	ret = pci_register_driver(&glandagpu_pci_driver);
> +	if (ret) {
> +		pr_err("GlandaGPU: Failed to register PCI driver\n");
> +		platform_driver_unregister(&glandagpu_driver);
> +		return ret;
> +	}
> +
> +	pr_info("GlandaGPU: Module loaded successfully\n");

Drop. Kernel does not print such messages. It pollutes dmesg even
without actual hardware.


> +	return 0;
> +}
> +
> +static void __exit glandagpu_exit(void)
> +{
> +	pci_unregister_driver(&glandagpu_pci_driver);
> +	platform_driver_unregister(&glandagpu_driver);
> +	pr_info("GlandaGPU: Module unloaded\n");

Same here.

> +}
> +
> +module_init(glandagpu_init);
> +module_exit(glandagpu_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Leander Kieweg <[email protected]>");
> +MODULE_DESCRIPTION("DRM driver for GlandaGPU, an FPGA-based 2D GPU with VGA output");
> -- 
> 2.43.0
>