Re: avoiding pci_disable_device()...

From: Takashi Iwai (tiwai_at_suse.de)
Date: 02/14/05

  • Next message: Jeff Garzik: "Re: avoiding pci_disable_device()..." 
    Date:	Mon, 14 Feb 2005 20:50:04 +0100
To: Greg KH <greg@kroah.com>

    At Mon, 14 Feb 2005 11:34:13 -0800,
    Greg KH wrote:
    >
    > On Mon, Feb 14, 2005 at 08:24:29PM +0100, Takashi Iwai wrote:
    > > At Mon, 14 Feb 2005 11:06:19 -0800,
    > > Greg KH wrote:
    > > >
    > > > > As a result, I have committed the attached patch to libata-2.6. In many
    > > > > cases, it is a "semantic fix", addressing the case
    > > > >
    > > > > * pci_request_regions() indicates hardware is in use
    > > > > * we rudely disable the in-use hardware
    > > > >
    > > > > that would not occur in practice.
    > > > >
    > > > > But better safe than sorry. Code cuts cut-n-pasted all over the place.
    > > > >
    > > > > I'm hoping one or two things will happen now:
    > > > > * janitors fix up the other PCI drivers along these lines
    > > > > * improve the PCI API so that pci_request_regions() is axiomatic
    > > >
    > > > Do you have any suggestions for how to do this?
    > >
    > > How about to add an exclusiveness check in pci_enable_device()?
    > > Most drivers suppose that the given pci resources are exclusively
    > > available.
    >
    > You mean only allow pci_enable_device() to work for the first caller of
    > it? I don't see how that would help this issue out.

    Well, for example, add a new pointer to indicate the driver accessing
    exclusively. And pci_enable_device() (maybe a new variant would be
    better for compatibility) checks whether this is free.

    The second caller wouldn't reach even to pci_request_regions() because
    of this check. So, no side-effect of pci_disable_device() in the
    error path.

    Takashi
    -
    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/

  • Next message: Jeff Garzik: "Re: avoiding pci_disable_device()..."

    Relevant Pages