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authorWitold Szczeponik <Witold.Szczeponik@gmx.net>2011-07-25 17:13:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-25 20:57:17 -0700
commit29df8d8f8702f0f53c1375015f09f04bc8d023c1 (patch)
tree32a7f6d0190bfdbe602bb969192010c91a0fbf6a /drivers/pnp/pnpacpi
parente57ee01750c4954fd0b5e3c6109cd4b870880eb9 (diff)
downloadlinux-linaro-stable-29df8d8f8702f0f53c1375015f09f04bc8d023c1.tar.gz
pnpacpi: register disabled resources
When parsing PnP ACPI resource structures, it may happen that some of the resources are disabled (in which case "the size" of the resource equals zero). The current solution is to skip these resources completely - with the unfortunate side effect that they are not registered despite the fact that they exist, after all. (The downside of this approach is that these resources cannot be used as templates for setting the actual device's resources because they are missing from the template.) The kernel's APM implementation does not suffer from this problem and registers all resources regardless of "their size". This patch fixes a problem with (at least) the vintage IBM ThinkPad 600E (and most likely also with the 600, 600X, and 770X which have a very similar layout) where some of its PnP devices support options where either an IRQ, a DMA, or an IO port is disabled. Without this patch, the devices can not be configured using the "/sys/bus/pnp/devices/*/resources" interface. The manipulation of these resources is important because the 600E has very demanding requirements. For instance, the number of IRQs is not sufficient to support all devices of the 600E. Fortunately, some of the devices, like the sound card's MPU-401 UART, can be configured to not use any IRQ, hence freeing an IRQ for a device that requires one. (Still, the device's "ResourceTemplate" requires an IRQ resource descriptor which cannot be created if the resource has not been registered in the first place.) As an example, the dependent sets of the 600E's CSC0103 device (the MPU-401 UART) are listed, with the patch applied, as: Dependent: 00 - Priority preferred port 0x300-0x330, align 0xf, size 0x4, 16-bit address decoding irq <none> High-Edge Dependent: 01 - Priority acceptable port 0x300-0x330, align 0xf, size 0x4, 16-bit address decoding irq 5,7,2/9,10,11,15 High-Edge (The same result is obtained when PNPBIOS is used instead of PnP ACPI.) Without the patch, the IRQ resource in the preferred option is not listed at all: Dependent: 00 - Priority preferred port 0x300-0x330, align 0xf, size 0x4, 16-bit address decoding Dependent: 01 - Priority acceptable port 0x300-0x330, align 0xf, size 0x4, 16-bit address decoding irq 5,7,2/9,10,11,15 High-Edge And in fact, the 600E's DSDT lists the disabled IRQ as an option, as can be seen from the following excerpt from the DSDT: Name (_PRS, ResourceTemplate () { StartDependentFn (0x00, 0x00) { IO (Decode16, 0x0300, 0x0330, 0x10, 0x04) IRQNoFlags () {} } StartDependentFn (0x01, 0x00) { IO (Decode16, 0x0300, 0x0330, 0x10, 0x04) IRQNoFlags () {5,7,9,10,11,15} } EndDependentFn () }) With this patch applied, a user space program - or maybe even the kernel - can allocate all devices' resources optimally. For the 600E, this means to find optimal resources for (at least) the serial port, the parallel port, the infrared port, the MWAVE modem, the sound card, and the MPU-401 UART. The patch applies the idea to register disabled resources to all types of resources, not just to IRQs, DMAs, and IO ports. At the same time, it mimics the behavior of the "pnp_assign_xxx" functions from "drivers/pnp/manager.c" where resources with "no size" are considered disabled. No regressions were observed on hardware that does not require this patch. The patch is applied against 2.6.39. NB: The kernel's current PnP interface does not allow for disabling individual resources using the "/sys/bus/pnp/devices/$device/resources" file. Assuming this could be done, a device could be configured to use a disabled resource using a simple series of calls: echo disable > /sys/bus/pnp/devices/$device/resources echo clear > /sys/bus/pnp/devices/$device/resources echo set irq disabled > /sys/bus/pnp/devices/$device/resources echo fill > /sys/bus/pnp/devices/$device/resources echo activate > /sys/bus/pnp/devices/$device/resources This patch addresses only the parsing of PnP ACPI devices. ChangeLog (v1 -> v2): - extend patch description - fix typo in patch itself Signed-off-by: Witold Szczeponik <Witold.Szczeponik@gmx.net> Cc: Len Brown <lenb@kernel.org> Cc: Adam Belay <abelay@mit.edu> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Matthew Garrett <mjg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/pnp/pnpacpi')
-rw-r--r--drivers/pnp/pnpacpi/rsparser.c52
1 files changed, 27 insertions, 25 deletions
diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c
index 100e4d9372f1..4a07cd96f787 100644
--- a/drivers/pnp/pnpacpi/rsparser.c
+++ b/drivers/pnp/pnpacpi/rsparser.c
@@ -509,15 +509,15 @@ static __init void pnpacpi_parse_dma_option(struct pnp_dev *dev,
struct acpi_resource_dma *p)
{
int i;
- unsigned char map = 0, flags;
+ unsigned char map = 0, flags = 0;
if (p->channel_count == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
for (i = 0; i < p->channel_count; i++)
map |= 1 << p->channels[i];
- flags = dma_flags(dev, p->type, p->bus_master, p->transfer);
+ flags |= dma_flags(dev, p->type, p->bus_master, p->transfer);
pnp_register_dma_resource(dev, option_flags, map, flags);
}
@@ -527,17 +527,17 @@ static __init void pnpacpi_parse_irq_option(struct pnp_dev *dev,
{
int i;
pnp_irq_mask_t map;
- unsigned char flags;
+ unsigned char flags = 0;
if (p->interrupt_count == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
bitmap_zero(map.bits, PNP_IRQ_NR);
for (i = 0; i < p->interrupt_count; i++)
if (p->interrupts[i])
__set_bit(p->interrupts[i], map.bits);
- flags = irq_flags(p->triggering, p->polarity, p->sharable);
+ flags |= irq_flags(p->triggering, p->polarity, p->sharable);
pnp_register_irq_resource(dev, option_flags, &map, flags);
}
@@ -547,10 +547,10 @@ static __init void pnpacpi_parse_ext_irq_option(struct pnp_dev *dev,
{
int i;
pnp_irq_mask_t map;
- unsigned char flags;
+ unsigned char flags = 0;
if (p->interrupt_count == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
bitmap_zero(map.bits, PNP_IRQ_NR);
for (i = 0; i < p->interrupt_count; i++) {
@@ -564,7 +564,7 @@ static __init void pnpacpi_parse_ext_irq_option(struct pnp_dev *dev,
}
}
- flags = irq_flags(p->triggering, p->polarity, p->sharable);
+ flags |= irq_flags(p->triggering, p->polarity, p->sharable);
pnp_register_irq_resource(dev, option_flags, &map, flags);
}
@@ -575,10 +575,10 @@ static __init void pnpacpi_parse_port_option(struct pnp_dev *dev,
unsigned char flags = 0;
if (io->address_length == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
if (io->io_decode == ACPI_DECODE_16)
- flags = IORESOURCE_IO_16BIT_ADDR;
+ flags |= IORESOURCE_IO_16BIT_ADDR;
pnp_register_port_resource(dev, option_flags, io->minimum, io->maximum,
io->alignment, io->address_length, flags);
}
@@ -587,11 +587,13 @@ static __init void pnpacpi_parse_fixed_port_option(struct pnp_dev *dev,
unsigned int option_flags,
struct acpi_resource_fixed_io *io)
{
+ unsigned char flags = 0;
+
if (io->address_length == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
pnp_register_port_resource(dev, option_flags, io->address, io->address,
- 0, io->address_length, IORESOURCE_IO_FIXED);
+ 0, io->address_length, flags | IORESOURCE_IO_FIXED);
}
static __init void pnpacpi_parse_mem24_option(struct pnp_dev *dev,
@@ -601,10 +603,10 @@ static __init void pnpacpi_parse_mem24_option(struct pnp_dev *dev,
unsigned char flags = 0;
if (p->address_length == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
if (p->write_protect == ACPI_READ_WRITE_MEMORY)
- flags = IORESOURCE_MEM_WRITEABLE;
+ flags |= IORESOURCE_MEM_WRITEABLE;
pnp_register_mem_resource(dev, option_flags, p->minimum, p->maximum,
p->alignment, p->address_length, flags);
}
@@ -616,10 +618,10 @@ static __init void pnpacpi_parse_mem32_option(struct pnp_dev *dev,
unsigned char flags = 0;
if (p->address_length == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
if (p->write_protect == ACPI_READ_WRITE_MEMORY)
- flags = IORESOURCE_MEM_WRITEABLE;
+ flags |= IORESOURCE_MEM_WRITEABLE;
pnp_register_mem_resource(dev, option_flags, p->minimum, p->maximum,
p->alignment, p->address_length, flags);
}
@@ -631,10 +633,10 @@ static __init void pnpacpi_parse_fixed_mem32_option(struct pnp_dev *dev,
unsigned char flags = 0;
if (p->address_length == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
if (p->write_protect == ACPI_READ_WRITE_MEMORY)
- flags = IORESOURCE_MEM_WRITEABLE;
+ flags |= IORESOURCE_MEM_WRITEABLE;
pnp_register_mem_resource(dev, option_flags, p->address, p->address,
0, p->address_length, flags);
}
@@ -655,18 +657,18 @@ static __init void pnpacpi_parse_address_option(struct pnp_dev *dev,
}
if (p->address_length == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
if (p->resource_type == ACPI_MEMORY_RANGE) {
if (p->info.mem.write_protect == ACPI_READ_WRITE_MEMORY)
- flags = IORESOURCE_MEM_WRITEABLE;
+ flags |= IORESOURCE_MEM_WRITEABLE;
pnp_register_mem_resource(dev, option_flags, p->minimum,
p->minimum, 0, p->address_length,
flags);
} else if (p->resource_type == ACPI_IO_RANGE)
pnp_register_port_resource(dev, option_flags, p->minimum,
p->minimum, 0, p->address_length,
- IORESOURCE_IO_FIXED);
+ flags | IORESOURCE_IO_FIXED);
}
static __init void pnpacpi_parse_ext_address_option(struct pnp_dev *dev,
@@ -677,18 +679,18 @@ static __init void pnpacpi_parse_ext_address_option(struct pnp_dev *dev,
unsigned char flags = 0;
if (p->address_length == 0)
- return;
+ flags |= IORESOURCE_DISABLED;
if (p->resource_type == ACPI_MEMORY_RANGE) {
if (p->info.mem.write_protect == ACPI_READ_WRITE_MEMORY)
- flags = IORESOURCE_MEM_WRITEABLE;
+ flags |= IORESOURCE_MEM_WRITEABLE;
pnp_register_mem_resource(dev, option_flags, p->minimum,
p->minimum, 0, p->address_length,
flags);
} else if (p->resource_type == ACPI_IO_RANGE)
pnp_register_port_resource(dev, option_flags, p->minimum,
p->minimum, 0, p->address_length,
- IORESOURCE_IO_FIXED);
+ flags | IORESOURCE_IO_FIXED);
}
struct acpipnp_parse_option_s {