* [PATCH] PCI: host-generic: Avoid reporting incorrect "missing "reg" property" error
@ 2026-01-19 5:06 Jess
2026-01-19 16:49 ` Will Deacon
0 siblings, 1 reply; 5+ messages in thread
From: Jess @ 2026-01-19 5:06 UTC (permalink / raw)
To: will, lpieralisi, kwilczynski, mani, robh, bhelgaas, linux-pci; +Cc: Jess
When the function pci_host_common_ecam_create() calls
of_address_to_resource() it assumes all errors from that callsite are due
to a missing "reg" property in the device tree node.
This can manifest when running the qemu "virt" board, with a 32-bit kernel
and `highmem=on`.
After the following calls:
of_address_to_resource()
-> __of_address_to_resource()
-> __of_address_resource_bounds()
this overflow check can fail due to PCI being out of range:
if (overflows_type(start, r->start))
return -EOVERFLOW;
This leads to the very confusing error message:
pci-host-generic 4010000000.pcie: host bridge /pcie@10000000 ranges:
pci-host-generic 4010000000.pcie: IO 0x003eff0000..0x003effffff -> 0x0000000000
pci-host-generic 4010000000.pcie: MEM 0x0010000000..0x003efeffff -> 0x0010000000
pci-host-generic 4010000000.pcie: MEM 0x8000000000..0xffffffffff -> 0x8000000000
pci-host-generic 4010000000.pcie: missing "reg" property
pci-host-generic 4010000000.pcie: probe with driver pci-host-generic failed with error -75
This commit gets rid of the confusing error message.
Link: https://www.qemu.org/docs/master/system/arm/virt.html
Signed-off-by: Jess <jess@jessie.cafe>
---
drivers/pci/controller/pci-host-common.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
index c473e7c03bac..04e1fef70c9c 100644
--- a/drivers/pci/controller/pci-host-common.c
+++ b/drivers/pci/controller/pci-host-common.c
@@ -31,10 +31,8 @@ struct pci_config_window *pci_host_common_ecam_create(struct device *dev,
struct pci_config_window *cfg;
err = of_address_to_resource(dev->of_node, 0, &cfgres);
- if (err) {
- dev_err(dev, "missing \"reg\" property\n");
+ if (err)
return ERR_PTR(err);
- }
bus = resource_list_first_type(&bridge->windows, IORESOURCE_BUS);
if (!bus)
--
2.51.2
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] PCI: host-generic: Avoid reporting incorrect "missing "reg" property" error
2026-01-19 5:06 [PATCH] PCI: host-generic: Avoid reporting incorrect "missing "reg" property" error Jess
@ 2026-01-19 16:49 ` Will Deacon
2026-01-20 0:44 ` [PATCH v2] " Jess
0 siblings, 1 reply; 5+ messages in thread
From: Will Deacon @ 2026-01-19 16:49 UTC (permalink / raw)
To: Jess; +Cc: lpieralisi, kwilczynski, mani, robh, bhelgaas, linux-pci
On Mon, Jan 19, 2026 at 06:06:45PM +1300, Jess wrote:
> When the function pci_host_common_ecam_create() calls
> of_address_to_resource() it assumes all errors from that callsite are due
> to a missing "reg" property in the device tree node.
>
> This can manifest when running the qemu "virt" board, with a 32-bit kernel
> and `highmem=on`.
>
> After the following calls:
> of_address_to_resource()
> -> __of_address_to_resource()
> -> __of_address_resource_bounds()
>
> this overflow check can fail due to PCI being out of range:
> if (overflows_type(start, r->start))
> return -EOVERFLOW;
>
> This leads to the very confusing error message:
> pci-host-generic 4010000000.pcie: host bridge /pcie@10000000 ranges:
> pci-host-generic 4010000000.pcie: IO 0x003eff0000..0x003effffff -> 0x0000000000
> pci-host-generic 4010000000.pcie: MEM 0x0010000000..0x003efeffff -> 0x0010000000
> pci-host-generic 4010000000.pcie: MEM 0x8000000000..0xffffffffff -> 0x8000000000
> pci-host-generic 4010000000.pcie: missing "reg" property
> pci-host-generic 4010000000.pcie: probe with driver pci-host-generic failed with error -75
>
> This commit gets rid of the confusing error message.
>
> Link: https://www.qemu.org/docs/master/system/arm/virt.html
> Signed-off-by: Jess <jess@jessie.cafe>
> ---
> drivers/pci/controller/pci-host-common.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
> index c473e7c03bac..04e1fef70c9c 100644
> --- a/drivers/pci/controller/pci-host-common.c
> +++ b/drivers/pci/controller/pci-host-common.c
> @@ -31,10 +31,8 @@ struct pci_config_window *pci_host_common_ecam_create(struct device *dev,
> struct pci_config_window *cfg;
>
> err = of_address_to_resource(dev->of_node, 0, &cfgres);
> - if (err) {
> - dev_err(dev, "missing \"reg\" property\n");
> + if (err)
> return ERR_PTR(err);
> - }
Maybe it would be better to print something more useful rather than removing
it entirely and leaving the poor luser guessing why their PCI isn't working?
How about one of:
"missing or malformed \"reg\" property\n"
"failed to parse ECAM base address from device-tree\n"
"failed to get ECAM resource\n"
Will
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v2] PCI: host-generic: Avoid reporting incorrect "missing "reg" property" error
2026-01-19 16:49 ` Will Deacon
@ 2026-01-20 0:44 ` Jess
2026-01-20 11:22 ` Will Deacon
2026-02-06 22:49 ` Bjorn Helgaas
0 siblings, 2 replies; 5+ messages in thread
From: Jess @ 2026-01-20 0:44 UTC (permalink / raw)
To: will; +Cc: bhelgaas, jess, kwilczynski, linux-pci, lpieralisi, mani, robh
When the function pci_host_common_ecam_create() calls
of_address_to_resource() it assumes all errors from that callsite are due
to a missing "reg" property in the device tree node.
This can manifest when running the qemu "virt" board, with a 32-bit kernel
and `highmem=on`.
After the following calls:
of_address_to_resource()
-> __of_address_to_resource()
-> __of_address_resource_bounds()
this overflow check can fail due to PCI being out of range:
if (overflows_type(start, r->start))
return -EOVERFLOW;
This leads to the very confusing error message:
pci-host-generic 4010000000.pcie: host bridge /pcie@10000000 ranges:
pci-host-generic 4010000000.pcie: IO 0x003eff0000..0x003effffff -> 0x0000000000
pci-host-generic 4010000000.pcie: MEM 0x0010000000..0x003efeffff -> 0x0010000000
pci-host-generic 4010000000.pcie: MEM 0x8000000000..0xffffffffff -> 0x8000000000
pci-host-generic 4010000000.pcie: missing "reg" property
pci-host-generic 4010000000.pcie: probe with driver pci-host-generic failed with error -75
Make the error message more generic.
Link: https://www.qemu.org/docs/master/system/arm/virt.html
Signed-off-by: Jess <jess@jessie.cafe>
---
drivers/pci/controller/pci-host-common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
index c473e7c03bac..d6258c1cffe5 100644
--- a/drivers/pci/controller/pci-host-common.c
+++ b/drivers/pci/controller/pci-host-common.c
@@ -32,7 +32,7 @@ struct pci_config_window *pci_host_common_ecam_create(struct device *dev,
err = of_address_to_resource(dev->of_node, 0, &cfgres);
if (err) {
- dev_err(dev, "missing \"reg\" property\n");
+ dev_err(dev, "missing or malformed \"reg\" property\n");
return ERR_PTR(err);
}
--
2.51.2
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2] PCI: host-generic: Avoid reporting incorrect "missing "reg" property" error
2026-01-20 0:44 ` [PATCH v2] " Jess
@ 2026-01-20 11:22 ` Will Deacon
2026-02-06 22:49 ` Bjorn Helgaas
1 sibling, 0 replies; 5+ messages in thread
From: Will Deacon @ 2026-01-20 11:22 UTC (permalink / raw)
To: Jess; +Cc: bhelgaas, kwilczynski, linux-pci, lpieralisi, mani, robh
On Tue, Jan 20, 2026 at 01:44:44PM +1300, Jess wrote:
> When the function pci_host_common_ecam_create() calls
> of_address_to_resource() it assumes all errors from that callsite are due
> to a missing "reg" property in the device tree node.
>
> This can manifest when running the qemu "virt" board, with a 32-bit kernel
> and `highmem=on`.
>
> After the following calls:
> of_address_to_resource()
> -> __of_address_to_resource()
> -> __of_address_resource_bounds()
>
> this overflow check can fail due to PCI being out of range:
> if (overflows_type(start, r->start))
> return -EOVERFLOW;
>
> This leads to the very confusing error message:
> pci-host-generic 4010000000.pcie: host bridge /pcie@10000000 ranges:
> pci-host-generic 4010000000.pcie: IO 0x003eff0000..0x003effffff -> 0x0000000000
> pci-host-generic 4010000000.pcie: MEM 0x0010000000..0x003efeffff -> 0x0010000000
> pci-host-generic 4010000000.pcie: MEM 0x8000000000..0xffffffffff -> 0x8000000000
> pci-host-generic 4010000000.pcie: missing "reg" property
> pci-host-generic 4010000000.pcie: probe with driver pci-host-generic failed with error -75
>
> Make the error message more generic.
>
> Link: https://www.qemu.org/docs/master/system/arm/virt.html
> Signed-off-by: Jess <jess@jessie.cafe>
> ---
> drivers/pci/controller/pci-host-common.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
> index c473e7c03bac..d6258c1cffe5 100644
> --- a/drivers/pci/controller/pci-host-common.c
> +++ b/drivers/pci/controller/pci-host-common.c
> @@ -32,7 +32,7 @@ struct pci_config_window *pci_host_common_ecam_create(struct device *dev,
>
> err = of_address_to_resource(dev->of_node, 0, &cfgres);
> if (err) {
> - dev_err(dev, "missing \"reg\" property\n");
> + dev_err(dev, "missing or malformed \"reg\" property\n");
> return ERR_PTR(err);
> }
>
> --
> 2.51.2
Couldn't have put it better myself :p
Acked-by: Will Deacon <will@kernel.org>
Will
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2] PCI: host-generic: Avoid reporting incorrect "missing "reg" property" error
2026-01-20 0:44 ` [PATCH v2] " Jess
2026-01-20 11:22 ` Will Deacon
@ 2026-02-06 22:49 ` Bjorn Helgaas
1 sibling, 0 replies; 5+ messages in thread
From: Bjorn Helgaas @ 2026-02-06 22:49 UTC (permalink / raw)
To: Jess; +Cc: will, bhelgaas, kwilczynski, linux-pci, lpieralisi, mani, robh
On Tue, Jan 20, 2026 at 01:44:44PM +1300, Jess wrote:
> When the function pci_host_common_ecam_create() calls
> of_address_to_resource() it assumes all errors from that callsite are due
> to a missing "reg" property in the device tree node.
>
> This can manifest when running the qemu "virt" board, with a 32-bit kernel
> and `highmem=on`.
>
> After the following calls:
> of_address_to_resource()
> -> __of_address_to_resource()
> -> __of_address_resource_bounds()
>
> this overflow check can fail due to PCI being out of range:
> if (overflows_type(start, r->start))
> return -EOVERFLOW;
>
> This leads to the very confusing error message:
> pci-host-generic 4010000000.pcie: host bridge /pcie@10000000 ranges:
> pci-host-generic 4010000000.pcie: IO 0x003eff0000..0x003effffff -> 0x0000000000
> pci-host-generic 4010000000.pcie: MEM 0x0010000000..0x003efeffff -> 0x0010000000
> pci-host-generic 4010000000.pcie: MEM 0x8000000000..0xffffffffff -> 0x8000000000
> pci-host-generic 4010000000.pcie: missing "reg" property
> pci-host-generic 4010000000.pcie: probe with driver pci-host-generic failed with error -75
>
> Make the error message more generic.
>
> Link: https://www.qemu.org/docs/master/system/arm/virt.html
> Signed-off-by: Jess <jess@jessie.cafe>
Applied to pci/controller/generic for v6.20, thanks!
> ---
> drivers/pci/controller/pci-host-common.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
> index c473e7c03bac..d6258c1cffe5 100644
> --- a/drivers/pci/controller/pci-host-common.c
> +++ b/drivers/pci/controller/pci-host-common.c
> @@ -32,7 +32,7 @@ struct pci_config_window *pci_host_common_ecam_create(struct device *dev,
>
> err = of_address_to_resource(dev->of_node, 0, &cfgres);
> if (err) {
> - dev_err(dev, "missing \"reg\" property\n");
> + dev_err(dev, "missing or malformed \"reg\" property\n");
> return ERR_PTR(err);
> }
>
> --
> 2.51.2
>
^ permalink raw reply [flat|nested] 5+ messages in thread
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Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2026-01-19 5:06 [PATCH] PCI: host-generic: Avoid reporting incorrect "missing "reg" property" error Jess
2026-01-19 16:49 ` Will Deacon
2026-01-20 0:44 ` [PATCH v2] " Jess
2026-01-20 11:22 ` Will Deacon
2026-02-06 22:49 ` Bjorn Helgaas
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