On Mon, 2014-07-07 at 14:57 +0200, Rafael J. Wysocki wrote:
> On Thursday, June 19, 2014 11:41:30 AM Andy Whitcroft wrote:
> > The recently merged change (in v3.14-rc6) to ACPI resource detection
> > (below) causes all zero length ACPI resources to be elided from the table:
> >
> > commit b355cee88e3b1a193f0e9a81db810f6f83ad728b
> > Author: Zhang Rui <rui.zh...@intel.com>
> > Date: Thu Feb 27 11:37:15 2014 +0800
> >
> > ACPI / resources: ignore invalid ACPI device resources
> >
> > This change has caused a regression in (at least) serial port detection
> > for a number of machines (see LP#1313981 [1]). These seem to represent
> > their IO regions (presumably incorrectly) as a zero length region.
> > Reverting the above commit restores these serial devices.
> >
> > For Zhang's case I wonder if this check could be tightened up to cover
> > only the zero base, something like the (untested) patch below.
> >
> > -apw
> >
> > [1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1313981
>
> I'm going to queue up the patch below for 3.16.
>
> Rui, can you please have a look at this and let me know if there's
> anything wrong with it?
>
> Rafael
>
>
> > From e5211c68278387ef65e483bcfedd5581a79ec783 Mon Sep 17 00:00:00 2001
> > From: Andy Whitcroft <a...@canonical.com>
> > Date: Thu, 19 Jun 2014 11:19:16 +0100
> > Subject: [PATCH] ACPI / Resources: only reject zero length resources based
> > at
> > address zero
> >
> > The recently merged change (in v3.14-rc6) to ACPI resource detection
> > (below) causes all zero length ACPI resources to be elided from the
> > table:
> >
> > commit b355cee88e3b1a193f0e9a81db810f6f83ad728b
> > Author: Zhang Rui <rui.zh...@intel.com>
> > Date: Thu Feb 27 11:37:15 2014 +0800
> >
> > ACPI / resources: ignore invalid ACPI device resources
> >
> > This change has caused a regression in (at least) serial port detection
> > for a number of machines (see LP#1313981 [1]). These seem to represent
> > their IO regions (presumably incorrectly) as a zero length region.
> > Reverting the above commit restores these serial devices.
> >
> > Only elide zero length resources which lie at address 0.
> >
> > Signed-off-by: Andy Whitcroft <a...@canonical.com>
The patch looks okay to me.
Acked-by: Zhang Rui <rui.zh...@intel.com>
thanks,
rui
> > ---
> > drivers/acpi/resource.c | 10 +++++-----
> > 1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> > index 0bdacc5..2ba8f02 100644
> > --- a/drivers/acpi/resource.c
> > +++ b/drivers/acpi/resource.c
> > @@ -77,7 +77,7 @@ bool acpi_dev_resource_memory(struct acpi_resource *ares,
> > struct resource *res)
> > switch (ares->type) {
> > case ACPI_RESOURCE_TYPE_MEMORY24:
> > memory24 = &ares->data.memory24;
> > - if (!memory24->address_length)
> > + if (!memory24->minimum && !memory24->address_length)
> > return false;
> > acpi_dev_get_memresource(res, memory24->minimum,
> > memory24->address_length,
> > @@ -85,7 +85,7 @@ bool acpi_dev_resource_memory(struct acpi_resource *ares,
> > struct resource *res)
> > break;
> > case ACPI_RESOURCE_TYPE_MEMORY32:
> > memory32 = &ares->data.memory32;
> > - if (!memory32->address_length)
> > + if (!memory32->minimum && !memory32->address_length)
> > return false;
> > acpi_dev_get_memresource(res, memory32->minimum,
> > memory32->address_length,
> > @@ -93,7 +93,7 @@ bool acpi_dev_resource_memory(struct acpi_resource *ares,
> > struct resource *res)
> > break;
> > case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
> > fixed_memory32 = &ares->data.fixed_memory32;
> > - if (!fixed_memory32->address_length)
> > + if (!fixed_memory32->address && !fixed_memory32->address_length)
> > return false;
> > acpi_dev_get_memresource(res, fixed_memory32->address,
> > fixed_memory32->address_length,
> > @@ -150,7 +150,7 @@ bool acpi_dev_resource_io(struct acpi_resource *ares,
> > struct resource *res)
> > switch (ares->type) {
> > case ACPI_RESOURCE_TYPE_IO:
> > io = &ares->data.io;
> > - if (!io->address_length)
> > + if (!io->minimum && !io->address_length)
> > return false;
> > acpi_dev_get_ioresource(res, io->minimum,
> > io->address_length,
> > @@ -158,7 +158,7 @@ bool acpi_dev_resource_io(struct acpi_resource *ares,
> > struct resource *res)
> > break;
> > case ACPI_RESOURCE_TYPE_FIXED_IO:
> > fixed_io = &ares->data.fixed_io;
> > - if (!fixed_io->address_length)
> > + if (!fixed_io->address && !fixed_io->address_length)
> > return false;
> > acpi_dev_get_ioresource(res, fixed_io->address,
> > fixed_io->address_length,
> >
>
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