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.zhang@xxxxxxxxx> > 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 <apw@xxxxxxxxxxxxx> > 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.zhang@xxxxxxxxx> > 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 <apw@xxxxxxxxxxxxx> > --- > 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, > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
