* [RFC PATCH 0/3] Pass resources to pci_create_bus() and fix MIPS PCI resources
@ 2011-08-24 6:24 Deng-Cheng Zhu
2011-08-24 6:24 ` [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources Deng-Cheng Zhu
` (2 more replies)
0 siblings, 3 replies; 11+ messages in thread
From: Deng-Cheng Zhu @ 2011-08-24 6:24 UTC (permalink / raw)
To: jbarnes, ralf
Cc: linux-pci, linux-kernel, linux-mips, eyal, zenon, dengcheng.zhu
For MIPS PCI, use the resources-list style to set up root resources rather than
filling in pci_bus->resource[] array directly. This will hide some ugly
implementation details.
In addition, change the pci_create_bus() interface to pass in available
resources to get them settled down early. This is to avoid possible resource
conflicts while doing pci_scan_slot() in pci_scan_child_bus(). Note that
pcibios_fixup_bus() can get rid of such conflicts, but it's done AFTER scanning
slots.
Deng-Cheng Zhu (3):
MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to
set up root resources
PCI: Pass available resources into pci_create_bus()
MIPS: PCI: Pass controller's resources to pci_create_bus() in
pcibios_scanbus()
arch/microblaze/pci/pci-common.c | 3 +-
arch/mips/pci/pci.c | 49 +++++++++++++++++++++++++++++++++++--
arch/powerpc/kernel/pci-common.c | 3 +-
arch/sparc/kernel/pci.c | 3 +-
arch/x86/pci/acpi.c | 2 +-
drivers/pci/probe.c | 15 ++++++++---
include/linux/pci.h | 3 +-
7 files changed, 66 insertions(+), 12 deletions(-)
^ permalink raw reply [flat|nested] 11+ messages in thread
* [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources
2011-08-24 6:24 [RFC PATCH 0/3] Pass resources to pci_create_bus() and fix MIPS PCI resources Deng-Cheng Zhu
@ 2011-08-24 6:24 ` Deng-Cheng Zhu
2011-08-24 14:35 ` Bjorn Helgaas
2011-08-24 6:24 ` [RFC PATCH 2/3] PCI: Pass available resources into pci_create_bus() Deng-Cheng Zhu
2011-08-24 6:24 ` [RFC PATCH 3/3] MIPS: PCI: Pass controller's resources to pci_create_bus() in pcibios_scanbus() Deng-Cheng Zhu
2 siblings, 1 reply; 11+ messages in thread
From: Deng-Cheng Zhu @ 2011-08-24 6:24 UTC (permalink / raw)
To: jbarnes, ralf
Cc: linux-pci, linux-kernel, linux-mips, eyal, zenon, dengcheng.zhu
Use this new style (instead of filling in the pci_bus->resource[] array
directly) to hide some ugly implementation details.
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
---
arch/mips/pci/pci.c | 11 +++++++++--
1 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c
index 33bba7b..7473214 100644
--- a/arch/mips/pci/pci.c
+++ b/arch/mips/pci/pci.c
@@ -261,6 +261,14 @@ static void pcibios_fixup_device_resources(struct pci_dev *dev,
}
}
+static void __devinit
+pcibios_setup_root_resources(struct pci_bus *bus, struct pci_controller *ctrl)
+{
+ pci_bus_remove_resources(bus);
+ pci_bus_add_resource(bus, ctrl->io_resource, 0);
+ pci_bus_add_resource(bus, ctrl->mem_resource, 0);
+}
+
void __devinit pcibios_fixup_bus(struct pci_bus *bus)
{
/* Propagate hose info into the subordinate devices. */
@@ -270,8 +278,7 @@ void __devinit pcibios_fixup_bus(struct pci_bus *bus)
struct pci_dev *dev = bus->self;
if (!dev) {
- bus->resource[0] = hose->io_resource;
- bus->resource[1] = hose->mem_resource;
+ pcibios_setup_root_resources(bus, hose);
} else if (pci_probe_only &&
(dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
pci_read_bridge_bases(bus);
--
1.7.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [RFC PATCH 2/3] PCI: Pass available resources into pci_create_bus()
2011-08-24 6:24 [RFC PATCH 0/3] Pass resources to pci_create_bus() and fix MIPS PCI resources Deng-Cheng Zhu
2011-08-24 6:24 ` [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources Deng-Cheng Zhu
@ 2011-08-24 6:24 ` Deng-Cheng Zhu
2011-08-24 14:28 ` Bjorn Helgaas
2011-08-24 6:24 ` [RFC PATCH 3/3] MIPS: PCI: Pass controller's resources to pci_create_bus() in pcibios_scanbus() Deng-Cheng Zhu
2 siblings, 1 reply; 11+ messages in thread
From: Deng-Cheng Zhu @ 2011-08-24 6:24 UTC (permalink / raw)
To: jbarnes, ralf
Cc: linux-pci, linux-kernel, linux-mips, eyal, zenon, dengcheng.zhu
Currently, after pci_create_bus(), resources available on the bus could be
handled by pci_scan_child_bus(). The problem is that, in
pci_scan_child_bus(), before calling arch-dependent pcibios_fixup_bus(),
PCI quirks will probably conflict (while doing pci_claim_resource()) with
resources like system controller's I/O resource that have not yet been
added to the bus. So, add those resources right before returning the newly
created bus in pci_create_bus().
A related discussion thread can be found here:
http://www.spinics.net/lists/mips/msg41654.html
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
---
arch/microblaze/pci/pci-common.c | 3 ++-
arch/powerpc/kernel/pci-common.c | 3 ++-
arch/sparc/kernel/pci.c | 3 ++-
arch/x86/pci/acpi.c | 2 +-
drivers/pci/probe.c | 15 +++++++++++----
include/linux/pci.h | 3 ++-
6 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
index 4cfae20..9c35aa6 100644
--- a/arch/microblaze/pci/pci-common.c
+++ b/arch/microblaze/pci/pci-common.c
@@ -1581,7 +1581,8 @@ static void __devinit pcibios_scan_phb(struct pci_controller *hose)
node ? node->full_name : "<NO NAME>");
/* Create an empty bus for the toplevel */
- bus = pci_create_bus(hose->parent, hose->first_busno, hose->ops, hose);
+ bus = pci_create_bus(hose->parent, hose->first_busno,
+ hose->ops, hose, NULL);
if (bus == NULL) {
printk(KERN_ERR "Failed to create bus for PCI domain %04x\n",
hose->global_number);
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 32656f1..2ede26a 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1703,7 +1703,8 @@ void __devinit pcibios_scan_phb(struct pci_controller *hose)
node ? node->full_name : "<NO NAME>");
/* Create an empty bus for the toplevel */
- bus = pci_create_bus(hose->parent, hose->first_busno, hose->ops, hose);
+ bus = pci_create_bus(hose->parent, hose->first_busno,
+ hose->ops, hose, NULL);
if (bus == NULL) {
pr_err("Failed to create bus for PCI domain %04x\n",
hose->global_number);
diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index 1e94f94..77c38bb 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -689,7 +689,8 @@ struct pci_bus * __devinit pci_scan_one_pbm(struct pci_pbm_info *pbm,
printk("PCI: Scanning PBM %s\n", node->full_name);
- bus = pci_create_bus(parent, pbm->pci_first_busno, pbm->pci_ops, pbm);
+ bus = pci_create_bus(parent, pbm->pci_first_busno,
+ pbm->pci_ops, pbm, NULL);
if (!bus) {
printk(KERN_ERR "Failed to create bus for %s\n",
node->full_name);
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index c953302..bab2113 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -353,7 +353,7 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
memcpy(bus->sysdata, sd, sizeof(*sd));
kfree(sd);
} else {
- bus = pci_create_bus(NULL, busnum, &pci_root_ops, sd);
+ bus = pci_create_bus(NULL, busnum, &pci_root_ops, sd, NULL);
if (bus) {
get_current_resources(device, busnum, domain, bus);
bus->subordinate = pci_scan_child_bus(bus);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 8473727..7735fe7 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1516,7 +1516,8 @@ unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
}
struct pci_bus * pci_create_bus(struct device *parent,
- int bus, struct pci_ops *ops, void *sysdata)
+ int bus, struct pci_ops *ops, void *sysdata,
+ struct pci_bus_resource *bus_res)
{
int error;
struct pci_bus *b, *b2;
@@ -1570,8 +1571,14 @@ struct pci_bus * pci_create_bus(struct device *parent,
pci_create_legacy_files(b);
b->number = b->secondary = bus;
- b->resource[0] = &ioport_resource;
- b->resource[1] = &iomem_resource;
+
+ /* Add initial resources to the bus */
+ if (bus_res != NULL) {
+ list_add_tail(&b->resources, &bus_res->list);
+ } else {
+ pci_bus_add_resource(b, &ioport_resource, 0);
+ pci_bus_add_resource(b, &iomem_resource, 0);
+ }
return b;
@@ -1592,7 +1599,7 @@ struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent,
{
struct pci_bus *b;
- b = pci_create_bus(parent, bus, ops, sysdata);
+ b = pci_create_bus(parent, bus, ops, sysdata, NULL);
if (b)
b->subordinate = pci_scan_child_bus(b);
return b;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8c230cb..5e1bacd 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -666,7 +666,8 @@ static inline struct pci_bus * __devinit pci_scan_bus(int bus, struct pci_ops *o
return root_bus;
}
struct pci_bus *pci_create_bus(struct device *parent, int bus,
- struct pci_ops *ops, void *sysdata);
+ struct pci_ops *ops, void *sysdata,
+ struct pci_bus_resource *bus_res);
struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
int busnr);
void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
--
1.7.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [RFC PATCH 3/3] MIPS: PCI: Pass controller's resources to pci_create_bus() in pcibios_scanbus()
2011-08-24 6:24 [RFC PATCH 0/3] Pass resources to pci_create_bus() and fix MIPS PCI resources Deng-Cheng Zhu
2011-08-24 6:24 ` [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources Deng-Cheng Zhu
2011-08-24 6:24 ` [RFC PATCH 2/3] PCI: Pass available resources into pci_create_bus() Deng-Cheng Zhu
@ 2011-08-24 6:24 ` Deng-Cheng Zhu
2 siblings, 0 replies; 11+ messages in thread
From: Deng-Cheng Zhu @ 2011-08-24 6:24 UTC (permalink / raw)
To: jbarnes, ralf
Cc: linux-pci, linux-kernel, linux-mips, eyal, zenon, dengcheng.zhu
Use the new interface of pci_create_bus() so that system controller's
resources are added to the root bus upon bus creation, thereby avoiding
conflicts with PCI quirks before pcibios_fixup_bus() gets the chance to do
right things in pci_scan_child_bus().
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
---
arch/mips/pci/pci.c | 38 +++++++++++++++++++++++++++++++++++++-
1 files changed, 37 insertions(+), 1 deletions(-)
diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c
index 7473214..a5ff6bc 100644
--- a/arch/mips/pci/pci.c
+++ b/arch/mips/pci/pci.c
@@ -76,11 +76,41 @@ pcibios_align_resource(void *data, const struct resource *res,
return start;
}
+static struct pci_bus_resource *
+controller_resources(const struct pci_controller *ctrl)
+{
+ struct pci_bus_resource *mem_res, *io_res;
+
+ mem_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
+ if (!mem_res)
+ goto err_out;
+
+ mem_res->res = ctrl->mem_resource;
+ mem_res->flags = 0;
+ INIT_LIST_HEAD(&mem_res->list);
+
+ io_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
+ if (!io_res) {
+ kfree(mem_res);
+ goto err_out;
+ }
+
+ io_res->res = ctrl->io_resource;
+ io_res->flags = 0;
+ list_add(&io_res->list, &mem_res->list);
+
+ return mem_res;
+err_out:
+ printk(KERN_ERR "Can't allocate PCI bus resource.\n");
+ return NULL;
+}
+
static void __devinit pcibios_scanbus(struct pci_controller *hose)
{
static int next_busno;
static int need_domain_info;
struct pci_bus *bus;
+ struct pci_bus_resource *bus_res;
if (!hose->iommu)
PCI_DMA_BUS_IS_PHYS = 1;
@@ -88,7 +118,13 @@ static void __devinit pcibios_scanbus(struct pci_controller *hose)
if (hose->get_busno && pci_probe_only)
next_busno = (*hose->get_busno)();
- bus = pci_scan_bus(next_busno, hose->pci_ops, hose);
+ bus_res = controller_resources(hose);
+ bus = pci_create_bus(NULL, next_busno, hose->pci_ops, hose, bus_res);
+ if (bus) {
+ bus->subordinate = pci_scan_child_bus(bus);
+ pci_bus_add_devices(bus);
+ }
+
hose->bus = bus;
need_domain_info = need_domain_info || hose->index;
--
1.7.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [RFC PATCH 2/3] PCI: Pass available resources into pci_create_bus()
2011-08-24 6:24 ` [RFC PATCH 2/3] PCI: Pass available resources into pci_create_bus() Deng-Cheng Zhu
@ 2011-08-24 14:28 ` Bjorn Helgaas
2011-08-25 6:56 ` Deng-Cheng Zhu
0 siblings, 1 reply; 11+ messages in thread
From: Bjorn Helgaas @ 2011-08-24 14:28 UTC (permalink / raw)
To: Deng-Cheng Zhu
Cc: jbarnes, ralf, linux-pci, linux-kernel, linux-mips, eyal, zenon
On Wed, Aug 24, 2011 at 12:24 AM, Deng-Cheng Zhu
<dengcheng.zhu@gmail.com> wrote:
> Currently, after pci_create_bus(), resources available on the bus could be
> handled by pci_scan_child_bus(). The problem is that, in
> pci_scan_child_bus(), before calling arch-dependent pcibios_fixup_bus(),
> PCI quirks will probably conflict (while doing pci_claim_resource()) with
> resources like system controller's I/O resource that have not yet been
> added to the bus. So, add those resources right before returning the newly
> created bus in pci_create_bus().
I like this approach a lot. Thanks for working it up. It's a nice
small change with very little impact to other architectures, and you
have a nice clear changelog. You might mention something about the
fact that by default, the bus starts out with all of ioport_resource
and iomem_resource -- that will mean something to people who know how
host bridges work.
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 8473727..7735fe7 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1516,7 +1516,8 @@ unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
> }
>
> struct pci_bus * pci_create_bus(struct device *parent,
> - int bus, struct pci_ops *ops, void *sysdata)
> + int bus, struct pci_ops *ops, void *sysdata,
> + struct pci_bus_resource *bus_res)
> {
> int error;
> struct pci_bus *b, *b2;
> @@ -1570,8 +1571,14 @@ struct pci_bus * pci_create_bus(struct device *parent,
> pci_create_legacy_files(b);
>
> b->number = b->secondary = bus;
> - b->resource[0] = &ioport_resource;
> - b->resource[1] = &iomem_resource;
> +
> + /* Add initial resources to the bus */
> + if (bus_res != NULL) {
> + list_add_tail(&b->resources, &bus_res->list);
> + } else {
> + pci_bus_add_resource(b, &ioport_resource, 0);
> + pci_bus_add_resource(b, &iomem_resource, 0);
> + }
Using pci_bus_add_resource() here *seems* like it should be the right
thing, but I don't think it will work correctly.
The problem is that struct pci_bus has both a table of resources
(bus->resource[]) *and* a list (bus->resources).
pci_bus_add_resource() always puts the new resource on the list, but
various arch code still references the table directly, e.g., sparc has
"pbus->resource[0] = &pbm->io_space" in pcibios_fixup_bus().
As written, I think this patch will break sparc because the host
bridge will end up with both pbm->io_space (in the table) and
ioport_resource (in the list).
I think something like this would work, though:
if (bus_res)
list_add_tail(&b->resources, &bus_res->list);
else {
b->resource[0] = &ioport_resource;
b->resource[1] = &iomem_resource;
}
Bjorn
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources
2011-08-24 6:24 ` [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources Deng-Cheng Zhu
@ 2011-08-24 14:35 ` Bjorn Helgaas
2011-08-25 6:41 ` Deng-Cheng Zhu
0 siblings, 1 reply; 11+ messages in thread
From: Bjorn Helgaas @ 2011-08-24 14:35 UTC (permalink / raw)
To: Deng-Cheng Zhu
Cc: jbarnes, ralf, linux-pci, linux-kernel, linux-mips, eyal, zenon
On Wed, Aug 24, 2011 at 12:24 AM, Deng-Cheng Zhu
<dengcheng.zhu@gmail.com> wrote:
> Use this new style (instead of filling in the pci_bus->resource[] array
> directly) to hide some ugly implementation details.
>
> Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
> ---
> arch/mips/pci/pci.c | 11 +++++++++--
> 1 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c
> index 33bba7b..7473214 100644
> --- a/arch/mips/pci/pci.c
> +++ b/arch/mips/pci/pci.c
> @@ -261,6 +261,14 @@ static void pcibios_fixup_device_resources(struct pci_dev *dev,
> }
> }
>
> +static void __devinit
> +pcibios_setup_root_resources(struct pci_bus *bus, struct pci_controller *ctrl)
> +{
> + pci_bus_remove_resources(bus);
> + pci_bus_add_resource(bus, ctrl->io_resource, 0);
> + pci_bus_add_resource(bus, ctrl->mem_resource, 0);
> +}
> +
> void __devinit pcibios_fixup_bus(struct pci_bus *bus)
> {
> /* Propagate hose info into the subordinate devices. */
> @@ -270,8 +278,7 @@ void __devinit pcibios_fixup_bus(struct pci_bus *bus)
> struct pci_dev *dev = bus->self;
>
> if (!dev) {
> - bus->resource[0] = hose->io_resource;
> - bus->resource[1] = hose->mem_resource;
> + pcibios_setup_root_resources(bus, hose);
> } else if (pci_probe_only &&
> (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
> pci_read_bridge_bases(bus);
I don't understand this patch.
Wouldn't it be enough to have [PATCH 2/3], which adds the
pci_create_bus() argument with nobody using it yet, then [PATCH 3/3],
which makes mips supply the new argument, and add a hunk to [PATCH
3/3] that completely removes the bus->resource fixups in
pcibios_fixup_bus() at the same time?
Bjorn
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources
2011-08-24 14:35 ` Bjorn Helgaas
@ 2011-08-25 6:41 ` Deng-Cheng Zhu
2011-08-25 15:34 ` Bjorn Helgaas
0 siblings, 1 reply; 11+ messages in thread
From: Deng-Cheng Zhu @ 2011-08-25 6:41 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: jbarnes, ralf, linux-pci, linux-kernel, linux-mips, eyal, zenon
2011/8/24 Bjorn Helgaas <bhelgaas@google.com>:
> Wouldn't it be enough to have [PATCH 2/3], which adds the
> pci_create_bus() argument with nobody using it yet, then [PATCH 3/3],
> which makes mips supply the new argument, and add a hunk to [PATCH
> 3/3] that completely removes the bus->resource fixups in
> pcibios_fixup_bus() at the same time?
>
> Bjorn
>
Do you mean to merge this patch to [PATCH 3/3]? OK, that's good!
Deng-Cheng
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [RFC PATCH 2/3] PCI: Pass available resources into pci_create_bus()
2011-08-24 14:28 ` Bjorn Helgaas
@ 2011-08-25 6:56 ` Deng-Cheng Zhu
0 siblings, 0 replies; 11+ messages in thread
From: Deng-Cheng Zhu @ 2011-08-25 6:56 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: jbarnes, ralf, linux-pci, linux-kernel, linux-mips, eyal, zenon
2011/8/24 Bjorn Helgaas <bhelgaas@google.com>:
> I like this approach a lot. Thanks for working it up. It's a nice
> small change with very little impact to other architectures, and you
> have a nice clear changelog. You might mention something about the
> fact that by default, the bus starts out with all of ioport_resource
> and iomem_resource -- that will mean something to people who know how
> host bridges work.
Thanks! And I'll add this info to the patch description.
> Using pci_bus_add_resource() here *seems* like it should be the right
> thing, but I don't think it will work correctly.
>
> The problem is that struct pci_bus has both a table of resources
> (bus->resource[]) *and* a list (bus->resources).
> pci_bus_add_resource() always puts the new resource on the list, but
> various arch code still references the table directly, e.g., sparc has
> "pbus->resource[0] = &pbm->io_space" in pcibios_fixup_bus().
>
> As written, I think this patch will break sparc because the host
> bridge will end up with both pbm->io_space (in the table) and
> ioport_resource (in the list).
Good catch! I overlooked this point.
> I think something like this would work, though:
>
> if (bus_res)
> list_add_tail(&b->resources, &bus_res->list);
> else {
> b->resource[0] = &ioport_resource;
> b->resource[1] = &iomem_resource;
> }
Yes, it should work.
Thanks again for your time,
Deng-Cheng
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources
2011-08-25 6:41 ` Deng-Cheng Zhu
@ 2011-08-25 15:34 ` Bjorn Helgaas
2011-08-25 23:14 ` Deng-Cheng Zhu
0 siblings, 1 reply; 11+ messages in thread
From: Bjorn Helgaas @ 2011-08-25 15:34 UTC (permalink / raw)
To: Deng-Cheng Zhu
Cc: jbarnes, ralf, linux-pci, linux-kernel, linux-mips, eyal, zenon
On Thu, Aug 25, 2011 at 12:41 AM, Deng-Cheng Zhu
<dengcheng.zhu@gmail.com> wrote:
> 2011/8/24 Bjorn Helgaas <bhelgaas@google.com>:
>> Wouldn't it be enough to have [PATCH 2/3], which adds the
>> pci_create_bus() argument with nobody using it yet, then [PATCH 3/3],
>> which makes mips supply the new argument, and add a hunk to [PATCH
>> 3/3] that completely removes the bus->resource fixups in
>> pcibios_fixup_bus() at the same time?
>>
>> Bjorn
>>
>
> Do you mean to merge this patch to [PATCH 3/3]? OK, that's good!
No, I just mean that I don't see why you need this patch at all. If
you pass the list of bus resources to pci_create_bus(), there's no
need to fix anything up later. Or am I missing something?
Bjorn
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources
2011-08-25 15:34 ` Bjorn Helgaas
@ 2011-08-25 23:14 ` Deng-Cheng Zhu
2011-08-25 23:23 ` Bjorn Helgaas
0 siblings, 1 reply; 11+ messages in thread
From: Deng-Cheng Zhu @ 2011-08-25 23:14 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: jbarnes, ralf, linux-pci, linux-kernel, linux-mips, eyal, zenon
2011/8/25 Bjorn Helgaas <bhelgaas@google.com>:
> No, I just mean that I don't see why you need this patch at all. If
> you pass the list of bus resources to pci_create_bus(), there's no
> need to fix anything up later. Or am I missing something?
Well, doing the root resource fixups in here is a *paranoid* way. It's to
deal with the 'unlikely' circumstance where controller_resources() returns
the NULL pointer in pcibios_scanbus() due to memory allocation failure.
Most of the time (always) it's nothing more than repeating the resource
list setup. But maybe we can do something like this:
if (unlikely(!dev && list_empty(&bus->resources))
pcibios_setup_root_resources(bus, hose);
What do you think?
Deng-Cheng
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources
2011-08-25 23:14 ` Deng-Cheng Zhu
@ 2011-08-25 23:23 ` Bjorn Helgaas
0 siblings, 0 replies; 11+ messages in thread
From: Bjorn Helgaas @ 2011-08-25 23:23 UTC (permalink / raw)
To: Deng-Cheng Zhu
Cc: jbarnes, ralf, linux-pci, linux-kernel, linux-mips, eyal, zenon
On Thu, Aug 25, 2011 at 5:14 PM, Deng-Cheng Zhu <dengcheng.zhu@gmail.com> wrote:
> 2011/8/25 Bjorn Helgaas <bhelgaas@google.com>:
>> No, I just mean that I don't see why you need this patch at all. If
>> you pass the list of bus resources to pci_create_bus(), there's no
>> need to fix anything up later. Or am I missing something?
>
> Well, doing the root resource fixups in here is a *paranoid* way. It's to
> deal with the 'unlikely' circumstance where controller_resources() returns
> the NULL pointer in pcibios_scanbus() due to memory allocation failure.
> Most of the time (always) it's nothing more than repeating the resource
> list setup. But maybe we can do something like this:
>
> if (unlikely(!dev && list_empty(&bus->resources))
> pcibios_setup_root_resources(bus, hose);
>
>
> What do you think?
I don't think it's worth it. Just check for failure of
controller_resources(), and if it fails, skip the pci_create_bus()
call. You've already printed a message (you might add the PCI
domain/bus number).
Bjorn
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2011-08-25 23:23 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-08-24 6:24 [RFC PATCH 0/3] Pass resources to pci_create_bus() and fix MIPS PCI resources Deng-Cheng Zhu
2011-08-24 6:24 ` [RFC PATCH 1/3] MIPS: PCI: Use pci_bus_remove_resources()/pci_bus_add_resource() to set up root resources Deng-Cheng Zhu
2011-08-24 14:35 ` Bjorn Helgaas
2011-08-25 6:41 ` Deng-Cheng Zhu
2011-08-25 15:34 ` Bjorn Helgaas
2011-08-25 23:14 ` Deng-Cheng Zhu
2011-08-25 23:23 ` Bjorn Helgaas
2011-08-24 6:24 ` [RFC PATCH 2/3] PCI: Pass available resources into pci_create_bus() Deng-Cheng Zhu
2011-08-24 14:28 ` Bjorn Helgaas
2011-08-25 6:56 ` Deng-Cheng Zhu
2011-08-24 6:24 ` [RFC PATCH 3/3] MIPS: PCI: Pass controller's resources to pci_create_bus() in pcibios_scanbus() Deng-Cheng Zhu
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