On Sun, Oct 06, 2024 at 09:40:00AM +0200, H. Nikolaus Schaller wrote:
> Hi,
>
> I found that the camera on our OMAP3 based system (GTA04) stopped working with v6.8-rc1.
> There was no bug in the camera driver but the OMAP3 ISP (image signal processor) emits
>
> [ 14.963684] omap3isp 480bc000.isp: failed to create ARM IOMMU mapping
> [ 15.010192] omap3isp 480bc000.isp: unable to attach to IOMMU
> [ 15.023376] omap3isp 480bc000.isp: isp_xclk_set_rate: cam_xclka set to 24685714 Hz (div 7)
> [ 15.065399] omap3isp: probe of 480bc000.isp failed with error -12
>
> Deeper analyses lead to this patch breaking operation. It is not fixed up to v6.12-rc1.
>
> What seems to happen (in 6.8-rc1 code):
>
> - omap_iommu_probe() passes &omap_iommu_ops to iommu_device_register()
> - iommu_device_register() stores the ops in iommu->ops (only)
> - __iommu_probe_device tries to read the ops from some fw_spec but not iommu->ops
Maybe like this?
@@ -1233,6 +1233,12 @@ static int omap_iommu_probe(struct platform_device *pdev)
err = iommu_device_register(&obj->iommu, &omap_iommu_ops, &pdev->dev);
if (err)
goto out_sysfs;
+ /*
+ * omap has a DT reprensetation but can't use the common DT
+ * code. Setting fwnode to NULL causes probe to be called for
+ * every device.
+ */
+ obj->iommu.fwnode = NULL;
obj->has_iommu_driver = true;
}
Jason
