Re: [PATCH 2.5.5] Conversion of hp100 to new PCI interface

From: Jean Tourrilhes (jt@bougret.hpl.hp.com)
Date: Tue Feb 26 2002 - 21:24:05 EST


On Tue, Feb 26, 2002 at 09:11:15PM -0500, Jeff Garzik wrote:
> >
> > + /* Conversion to new PCI API :
> > + * The memory block we use, lp->page_vaddr, was DMA allocated via
> > + * pci_alloc_consistent(), so we just need to "retreive" the
> > + * original mapping to bus/phys address - Jean II */
> > ringptr->pdl = pdlptr + 1;
> > - ringptr->pdl_paddr = virt_to_bus(pdlptr + 1);
> > + ringptr->pdl_paddr = virt_to_phys(pdlptr + 1);
>
> Nope.. You need to use the mapping value obtained from
> pci_alloc_consistent...

        I don't understand the objection. The memory has been declared
as DMA and the system already manages it as such. What's the catch ?
        If I can't use virt_to_phys(), can I have a function that does
exactly the same ? The new API is heavy enough, and if drivers can't
have something like this it's just messy...
        Just define something like :
------------------------------------------
static inline dma_addr_t pci_map_alloc(struct pci_dev *hwdev, void *ptr)
{
        ret virt_to_phys(ptr);
}
------------------------------------------

> Note for ISA (and EISA and VLB) devices, you also call
> pci_alloc_consistent. You pass NULL for the pci device.

        That's what I do. But I don't claim it's tested.
        By the way, it seems weird to prefix all those functions with
"pci_" where in fact they are only loosely related to PCI stuff.
        Also, on the inconsistent side, most functions handle pci_dev
== NULL, but not all, and it's not well documented. For example, if
you pass NULL to pci_set_dma_mask(), it will kaboom !

> Jeff

        Jean
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