Re: [PATCH 5/6] PCI: acpiphp: look _RMV method a bit deeper in thehierarhcy

From: Mika Westerberg
Date: Tue Jun 25 2013 - 14:27:51 EST


On Tue, Jun 25, 2013 at 09:15:47PM +0300, Andy Shevchenko wrote:
> On Tue, Jun 25, 2013 at 7:22 PM, Mika Westerberg
> <mika.westerberg@xxxxxxxxxxxxxxx> wrote:
>
> > The acpiphp driver finds out whether the device is hotpluggable by checking
> > whether it has _RMV method behind it (and if it returns 1). However, at
> > least Acer Aspire S5 with Thunderbolt host router has this method placed
> > behind device called EPUP (endpoint upstream port?) and not directly behind
> > the root port as can be seen from the ASL code below:
>
> []
>
>
> > +static acpi_status pcihp_evaluate_rmv(acpi_handle handle, u32 lvl,
> > + void *context, void **return_not_used)
> > +{
> > + unsigned long long *removable = context;
> > + unsigned long long value;
> > + acpi_status status;
> > +
> > + status = acpi_evaluate_integer(handle, "_RMV", NULL, &value);
> > + if (ACPI_SUCCESS(status) && value) {
>
> So, there is a chance the caller gets back uninitialized *context.
> Let's assume that is by design.
>
> > + *removable = value;
> > + return AE_CTRL_TERMINATE;
> > + }
> > + return AE_OK;
> > +}
>
>
> > +static bool pcihp_is_removable(acpi_handle handle, size_t depth)
> > +{
> > + unsigned long long removable = 0;
> > + acpi_status status;
> > +
> > + status = pcihp_evaluate_rmv(handle, 0, &removable, NULL);
> > + if ((status == AE_CTRL_TERMINATE) && removable)
>
> Here you already have removable not equal zero.

Hmm, removable is initialized to zero just few lines above... Did I miss
something obvious?

> Internal braces could be removed, but it's up top you.

I'll remove them in the next revision.

Thanks.
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