Messages in this thread | | | Date | Tue, 19 Aug 2003 14:54:52 -0700 (PDT) | From | Jon Smirl <> | Subject | Re: Standard driver call to enable/disable PCI ROM |
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--- Russell King <rmk@arm.linux.org.uk> 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 <rmk@arm.linux.org.uk> 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 jonsmirl@yahoo.com
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