Re: [net-next PATCH v3 1/1] atm: remove deprecated use of pci api

[Quentin Lambert <lambert.quentin@gmail.com>]

On 16/01/2015 15:52, chas williams - CONTRACTOR wrote:
> On Fri, 16 Jan 2015 15:10:25 +0100
> Quentin Lambert <lambert.quentin@gmail.com> wrote:
>
>
>>> -    u32 dma_addr = pci_map_single((struct pci_dev*)fore200e->bus_dev, virt_addr, size, direction);
>>> +    u32 dma_addr = dma_map_single(&((struct pci_dev *) fore200e->bus_dev)->dev, virt_addr, size, direction);
>>>    
>>>        DPRINTK(3, "PCI DVMA mapping: virt_addr = 0x%p, size = %d, direction = %d,  --> dma_addr = 0x%08x\n",
>>>    	    virt_addr, size, direction, dma_addr);
>>>
>> []
>>
>> I am going try to make similar changes in some other part of the kernel and
>> I was wondering if you could explain how you decided it wasn't necessary to
>> check for "((struct pci_dev *) fore200e->bus_dev" nullity for instance.
> This gets set up in fore200e_pca_detect() which is pretty early in the
> intialization process.  We don't get as far as using any of the "DVMA"
> stubs unless pci_enable_device() succeeds, meaning pci_dev is good, and
> fore200e->bus_dev is assigned to pci_dev (around line 2724).
>
> fore200e->bus_dev is never cleared back to NULL, but obviously you
> shouldn't be using any of the DMA routines after disabling the pci
> device.  Hopefully the driver shuts down in an orderly fashion such
> that all DMA is over by the time the driver disables the pci device.
Thank you