Hi Bjorn,
On Fri, Jan 23, 2015 at 03:34:12PM -0600, Bjorn Helgaas wrote:
> [+cc Fabio]
>
> On Thu, Jan 08, 2015 at 02:17:36PM -0800, Dmitry Torokhov wrote:
> > Even though platform bus is not hot-pluggable, devices on it can be unbound
> > from the driver and bound back to it via sysfs, so we should not be using
> > __init annotations on probe() and __exit annotations on remove() methods.
>
> I don't completely understand this problem. Does this mean there should be
> no __init/__exit annotations in these drivers at all? If other PCI host
> bridge drivers have the same problem, I'd like to fix them all at once.
Basically they should not use __init/__exit, unless you take explicit
steps to make sure that devices can't be unbound and bound again later
via sysfs by setting driver->suppress_bind_attrs and/or using
platform_driver_probe(). Note that if you use platform_driver_probe()
then your driver can't cope with -EPROBE_DEFER reported by any of the
subsystems it might be using.
>
> For example, after applying this patch, ks_pcie_probe() is non-__init, but
> it calls ks_add_pcie_port(), which is still __init. I thought that was
> illegal.
My bad, I missed that. The __init marking on ks_add_pcie_port() shoudl
be removed as well.
>
> I'm not sure about module_platform_driver_probe() either; it generates
> __init and __exit functions. Should those annotations be removed, too?
module_platform_driver_probe() does internally platform_driver_probe()
so it is OK for that probe function be __init (because we'd suppress
sysfs bind/unbind and deferred probing so discaring init section is
safe).
Note that above applied to driver's ->probe() and ->remove() code paths
only. Marking module init/exit code as __init and __exit is still right
thing to do.
Thanks.
>
> > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > ---
> >
> > Not tested, found by casual code inspection.
> >
> > drivers/pci/host/pci-keystone.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
> > index 1b893bc..7b84e1d 100644
> > --- a/drivers/pci/host/pci-keystone.c
> > +++ b/drivers/pci/host/pci-keystone.c
> > @@ -332,7 +332,7 @@ static const struct of_device_id ks_pcie_of_match[] = {
> > };
> > MODULE_DEVICE_TABLE(of, ks_pcie_of_match);
> >
> > -static int __exit ks_pcie_remove(struct platform_device *pdev)
> > +static int ks_pcie_remove(struct platform_device *pdev)
> > {
> > struct keystone_pcie *ks_pcie = platform_get_drvdata(pdev);
> >
> > @@ -341,7 +341,7 @@ static int __exit ks_pcie_remove(struct platform_device *pdev)
> > return 0;
> > }
> >
> > -static int __init ks_pcie_probe(struct platform_device *pdev)
> > +static int ks_pcie_probe(struct platform_device *pdev)
> > {
> > struct device *dev = &pdev->dev;
> > struct keystone_pcie *ks_pcie;
> > @@ -398,9 +398,9 @@ fail_clk:
> > return ret;
> > }
> >
> > -static struct platform_driver ks_pcie_driver __refdata = {
> > +static struct platform_driver ks_pcie_driver = {
> > .probe = ks_pcie_probe,
> > - .remove = __exit_p(ks_pcie_remove),
> > + .remove = ks_pcie_remove,
> > .driver = {
> > .name = "keystone-pcie",
> > .owner = THIS_MODULE,
> > --
> > 2.2.0.rc0.207.ga3a616c
> >
> >
> > --
> > Dmitry
--
Dmitry
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