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    SubjectRe: Standard driver call to enable/disable PCI ROM
    --- Russell King <> wrote:
    > On Tue, Aug 19, 2003 at 02:17:35PM -0700, David S. Miller wrote:
    > > On Tue, 19 Aug 2003 21:52:46 +0100
    > > Russell King <> wrote:
    > > > new |= res->flags & PCI_ROM_ADDRESS_ENABLE;
    > > > reg = dev->rom_base_reg;
    > >
    > > A word of caution, please do not enable PCI ROMs lightly.
    > >
    > > There are many devices which stop responding to MEM and IO
    > > space once their ROM is enabled, Qlogic-ISP chips are one
    > > such device and there are several others.

    I'm doing this in the device driver for the device, so I know it is ok to do.

    > However, there are device drivers which want to access the ROM for
    > whatever reason, and we should provide a standard way to allow
    > drivers to enable / disable ROM access for architecture portability
    > reasons (so that VGA drivers can find tables in their ROMs for
    > instance.)

    In my case I need access to tables in the ROM.

    > Since this is critical to some devices, maybe their drivers should
    > consider ensuring that the ROM resources are disabled upon driver
    > initialisation of the device?

    My driver can be load/unloaded so I need to turn the ROM on each
    time to get to the tables. I also don't like calling release_resource()
    directly from my driver since that looks like an internal PCI driver call.

    As to pcibios_resource_to_bus()....

    I called pci_assign_resource() which calls pci_update_resource()
    which calls pcibios_resource_to_bus().

    I see now that pci_assign_resource() will return with the ROM
    enabled. I believe I have also hit cases where ROM was assigned
    an address but not enabled. Do I still need to call
    pcibios_resource_to_bus() if I am just enabling the ROM?

    Do I need to call pcibios_resource_to_bus() when disabling the ROM?

    Jon Smirl

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