On Wed, 7 Mar 2018, Michael Schmitz wrote: > The major obstacle now seems to be dynamic allocation of the driver > private data and storing a pointer to that in a way that it can be > retrieved using just the esp pointer. dev_set_drvdata(esp->dev, zep) > causes the module load to crash ... I've just noticed that most esp drivers do this: static int esp_foo_probe(struct platform_device *dev) { ... esp->dev = dev; ... } But the esp->dev->dev dereferencing sometimes gets overlooked, resulting in a pointer to a struct platform_device being used where a pointer to a struct device should be used (i.e. dma_*() calls). I will look into fixing this up. sun_esp.c doesn't have this problem, but the other drivers do. I don't think any of that applies to your zorro_esp code because the version you sent does this, esp->dev = &z->dev; which seems fine to me. But it could end up more convenient to use the sun_esp approach and set esp->dev = z. I suspect that the problem with zorro_esp is that sometimes you use the esp->dev->driver_data pointer as the struct Scsi_Host pointer, and at other times you use it for the struct zorro_driver_data pointer. (I think I see now why you put the esp pointer in struct zorro_driver_data.) If you like, email the current version to me or push it to a repo somewhere and I'll take a look at it. --