Re: [RESEND PATCH v2 1/4] PCI: Ignore resource_alignment if PCI_PROBE_ONLY was set\\

[Yongji Xie]

On 2016/6/21 10:16, Yongji Xie wrote:

> On 2016/6/21 9:43, Bjorn Helgaas wrote:
>
> > On Thu, Jun 02, 2016 at 01:46:48PM +0800, Yongji Xie wrote:
> > > The resource_alignment will releases memory resources allocated
> > > by firmware so that kernel can reassign new resources later on.
> > > But this will cause the problem that no resources can be
> > > allocated by kernel if PCI_PROBE_ONLY was set, e.g. on pSeries
> > > platform because PCI_PROBE_ONLY force kernel to use firmware
> > > setup and not to reassign any resources.
> > >
> > > To solve this problem, this patch ignores resource_alignment
> > > if PCI_PROBE_ONLY was set.
> > >
> > > Signed-off-by: Yongji Xie <xyjxie@xxxxxxxxxxxxxxxxxx>
> > > ---
> > >   drivers/pci/pci.c |    6 ++++++
> > >   1 file changed, 6 insertions(+)
> > >
> > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > > index c8b4dbd..a259394 100644
> > > --- a/drivers/pci/pci.c
> > > +++ b/drivers/pci/pci.c
> > > @@ -4761,6 +4761,12 @@ static resource_size_t 
> > > pci_specified_resource_alignment(struct pci_dev *dev)
> > >       spin_lock(&resource_alignment_lock);
> > >       p = resource_alignment_param;
> > >       while (*p) {
> > > +        if (pci_has_flag(PCI_PROBE_ONLY)) {
> > > +            printk(KERN_ERR "PCI: Ignore resource_alignment 
> > > parameter: %s with PCI_PROBE_ONLY set\n",
> > > +                    p);
> > > +            *p = 0;
> > > +            break;
> > Wouldn't it be simpler to make pci_set_resource_alignment_param() fail
> > if PCI_PROBE_ONLY is set?
>
> I add the check here because I want to print some logs so that users
> could know the reason why resource_alignment doesn't work when
> they add this parameter.
>
> Thanks,
> Yongji

Sorry, please ignore the previous reply. I didn't add this check in
pci_set_resource_alignment_param() because PCI_PROBE_ONLY
may be set after we parse "resource_alignment".

And it seems that printk_once() may be better here so that
we don't need to set *p = 0.

Thanks,
Yongji

> > > +        }
> > >           count = 0;
> > >           if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
> > >                               p[count] == '@') {
> > > --
> > > 1.7.9.5
> > >
> > > --
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