Re: [RFC PATCH v2 0/3] prerequisites for device reserved local mem rework

From: Fredrik Noring
Date: Thu May 16 2019 - 09:56:48 EST


Hi Laurentiu,

> > The kernel oopses with "unable to handle kernel paging request at virtual
> > address 000aba0b" in hcd_alloc_coherent via usb_hcd_map_urb_for_dma.
>
> By any chance, does this address looks like the dma_addr that the device
> should target?

Yes, that looks like a typical device address suitable for its DMA.

> Actually, I think I'm misusing genalloc and also it appears that i need
> to add a mapping on the phys address. So my plan is to change the
> "unsigned long virt" to be the void * returned by the mapping operation
> and the phys_addr_t be the dma_addr_t. I'll return with a patch.

Great, I'm happy to test your next patch revision.

Fredrik