Re: [Xen-devel] Re: [PATCH] Modpost section mismatch fix

[Raghavendra D Prabhu]

* On Thu, Jul 07, 2011 at 12:24:54PM -0400, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> wrote:
> > Tested it. Works now.
>
> Ok, Stuck Tested-by on the patch. Hopefully Linus hasn't pulled it yet.
Ok.
> > Reviewed-by: Raghavendra Prabhu <rprabhu@xxxxxxxxxxx>

> > Also,
> > The condition for acpi_gsi_to_irq can be removed since it always returns zero.
>
> The function might in the future return something that is non-zero
> and we should guard for it. Also you make 'irq' be unsigned which is not
> good as the IRQ 0 is a valid value - and with making it unsigned if it is
> set to -1 (the -1 is the invalid IRQ value) the check for 'irq != gsi'
> will be true and and we will pass in -1 casted to unsigned. That is a
> large value and not the right thing we want to pass to xen_register_gsi.

My rationale for the unsigned part was that acpi_gsi_to_irq always
assigns a positive value (>= 0) to the irq passed (as unsigned
argument). But even otherwise that shouldn't make much of difference I guess.

Also,
I had sent another change (oneline) for the file
arch/x86/xen/platform-pci-unplug.c for check_platform_magic, looks like that has not gone into
the pull request for Linus.
> > ============================================
> >  diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
> >  index f567965..3faa55b 100644
> >  --- a/arch/x86/pci/xen.c
> >  +++ b/arch/x86/pci/xen.c
> >  @@ -405,7 +405,7 @@ static __init void xen_setup_acpi_sci(void)
> >          int rc;
> >          int trigger, polarity;
> >          int gsi = acpi_sci_override_gsi;
> >  -       int irq = -1;
> >  +       unsigned int irq = 0u;
> >          int gsi_override = -1;

> >          if (!gsi)
> >  @@ -435,11 +435,10 @@ static __init void xen_setup_acpi_sci(void)
> >           * setup as we had setup IRQ 20 for it).
> >           */
> >          /* Check whether the GSI != IRQ */
> >  -       if (acpi_gsi_to_irq(gsi, &irq) == 0) {
> >  -               if (irq >= 0 && irq != gsi)
> >  -                       /* Bugger, we MUST have that IRQ. */
> >  -                       gsi_override = irq;
> >  -       }
> >  +       acpi_gsi_to_irq(gsi, &irq);
> >  +       if (irq != gsi)
> >  +               /* Bugger, we MUST have that IRQ. */
> >  +               gsi_override = irq;

> >          gsi = xen_register_gsi(gsi, gsi_override, trigger, polarity);
> >          printk(KERN_INFO "xen: acpi sci %d\n", gsi);


> > --------------------------
> > Raghavendra Prabhu
> > GPG Id : 0xD72BE977
> > Fingerprint: B93F EBCB 8E05 7039 CD3C A4B8 A616 DCA1 D72B E977
> > www: wnohang.net
>
>
>
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> > http://lists.xensource.com/xen-devel
--------------------------
Raghavendra Prabhu
GPG Id : 0xD72BE977
Fingerprint: B93F EBCB 8E05 7039 CD3C A4B8 A616 DCA1 D72B E977
www: wnohang.net

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