[lkml]   [2006]   [Feb]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 0/6] PCI legacy I/O port free driver (take2)
Benjamin Herrenschmidt wrote:
>>Here, there are many PCI devices that provide both I/O port and MMIO
>>interface, and some of those devices can be handled without using I/O
>>port interface. The reason why such devices provide I/O port interface
>>is for compatibility to legacy OSs. So this kind of devices should
>>work even if enough I/O port resources are not assigned. The "PCI
>>Local Bus Specification Revision 3.0" also mentions about this topic
>>(Please see p.44, "IMPLEMENTATION NOTE"). On the current linux,
>>unfortunately, this kind of devices don't work if I/O port resources
>>are not assigned, because pci_enable_device() for those devices fails.
> Which is where the real problem is ... I'm afraid you are doing a
> workaround for the wrong issue... do we really need to assign all
> resources to the device at pci_enable_device() time ? Yeah, I know, that
> sounds gross... but think about it... doesn't pci_request_region(s) look
> like a better spot ? Or maybe we should change pci_enable_device()
> itself to take a mask of BARs that are relevant. That would help dealing
> with a couple of other cases of devices where some BARs really need to
> be ignored...
> The later is probably the best approach without breaking everything, by
> having a new pci_enable_resources(mask) that would take a mask of BARs
> to enable, with pci_enable_device() becoming just a call to the former
> for all BARs ....
> Ben.

I guess the existing pci_enable_device_bars() is very similar to
your pci_enable_resources(). We already discussed it at:

Kenji Kaneshige
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2006-02-23 07:05    [W:0.090 / U:0.820 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site