lkml.org 
[lkml]   [2013]   [Feb]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Date
    SubjectRe: [PATCH v2 25/26] PCI: Disable mem in the ioapic removing path
    On Fri, Feb 8, 2013 at 12:28 PM, Yinghai Lu <yinghai@kernel.org> wrote:
    > For physical hot plug should be ok, but for remove/rescan path will
    > need us to disable that.
    >
    > otherwise rescan mmio resource for pci ioapic device will not be
    > sized and allocated, aka skiped.

    When we scan other PCI devices, we can size memory BARs even if
    PCI_COMMAND_MEMORY is already set. So there must be something
    different about IOAPICs? Or maybe it's something different about
    rescan vs. the initial scan?

    > For ioapic_probe:pci_enable_device will not enable the device
    > correctly, and will bail out early.

    Exactly where and why do we bail out early? The only early bail out I
    see is where __pci_enable_device_flags() returns if "dev->enable_cnt >
    1". Is that what you mean?

    > So we can just disable mmio for all removing case, and that will not hurt
    > real hotplug path.

    > Signed-off-by: <yinghai@kernel.org>
    > ---
    > drivers/pci/ioapic.c | 13 +++++++++++++
    > 1 file changed, 13 insertions(+)
    >
    > diff --git a/drivers/pci/ioapic.c b/drivers/pci/ioapic.c
    > index 3c6bbdd..8dacfd0 100644
    > --- a/drivers/pci/ioapic.c
    > +++ b/drivers/pci/ioapic.c
    > @@ -88,6 +88,17 @@ exit_free:
    > return -ENODEV;
    > }
    >
    > +static void pci_disable_device_mem(struct pci_dev *dev)
    > +{
    > + u16 pci_command;
    > +
    > + pci_read_config_word(dev, PCI_COMMAND, &pci_command);
    > + if (pci_command & PCI_COMMAND_MEMORY) {
    > + pci_command &= ~PCI_COMMAND_MEMORY;
    > + pci_write_config_word(dev, PCI_COMMAND, pci_command);
    > + }
    > +}
    > +
    > static void ioapic_remove(struct pci_dev *dev)
    > {
    > struct ioapic *ioapic = pci_get_drvdata(dev);
    > @@ -95,6 +106,8 @@ static void ioapic_remove(struct pci_dev *dev)
    > acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base);
    > pci_release_region(dev, 0);
    > pci_disable_device(dev);
    > + /* need to disable it, otherwise remove/rescan will not work */
    > + pci_disable_device_mem(dev);
    > kfree(ioapic);
    > }
    >
    > --
    > 1.7.10.4
    >


    \
     
     \ /
      Last update: 2013-02-08 23:02    [W:4.143 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site