Messages in this thread | | | Date | Wed, 20 Feb 2002 17:03:09 -0500 | From | Jeff Garzik <> | Subject | Re: Q: PCI Driver ioremap |
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David Stroupe wrote: > > I am creating a PCI driver for a custom card and want to write 0xffff to > a location offset from the base by 0x48 and > have the following code: > > <snip> > unsigned int io_addr; > unsigned int io_size; > void* base; > pci_enable_device (pdev) > io_addr = pci_resource_start(pdev, 0); > io_size = pci_resource_len(pdev, 0); > if ((pci_resource_flags(pdev, 0) & IORESOURCE_MEM)){ > if(check_mem_region(io_addr, io_size)) > DBG("Already In Use");//this is never reached > request_mem_region(io_addr, io_size , "Card Driver");
In 2.4 and later, check request_mem_region return value, and never call check_mem_region.
> base=ioremap(io_addr, io_size); > if(base==0) > DBG("memory mapped wrong\n");//this is never reached > writew(0xffff, base + 0x48); > <snip> > > The card is found, io_addr = 0xe9011000 and io_size = 0x200. > > The write is unsuccessful or at least the data never reaches the card. > What am I doing incorrectly?
Looks correct to me... maybe you need to do readw(base + 0x48) to flush the transaction?
-- Jeff Garzik | "Why is it that attractive girls like you Building 1024 | always seem to have a boyfriend?" MandrakeSoft | "Because I'm a nympho that owns a brewery?" | - BBC TV show "Coupling" - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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