* Re: [PATCH] PCI: Restrict device disabled status check to DT
[not found] <20230419193513.708818-1-robh@kernel.org>
@ 2023-04-19 20:20 ` Bjorn Helgaas
2023-04-20 9:30 ` Vitaly Kuznetsov
0 siblings, 1 reply; 2+ messages in thread
From: Bjorn Helgaas @ 2023-04-19 20:20 UTC (permalink / raw)
To: Rob Herring
Cc: Bjorn Helgaas, Donald Hunter, Binbin Zhou, Liu Peibao,
Huacai Chen, Vitaly Kuznetsov, Jesse Brandeburg, Tony Nguyen,
Andy Shevchenko, linux-pci, linux-kernel, regressions
[+cc Vitaly, Jesse, Tony, Andy, regressions, regarding reports of
hang or crash during boot in igb driver, some with AWS Xen]
On Wed, Apr 19, 2023 at 02:35:13PM -0500, Rob Herring wrote:
> Commit 6fffbc7ae137 ("PCI: Honor firmware's device disabled status")
> checked the firmware device status for both DT and ACPI devices. That
> caused a regression in some ACPI systems. The exact reason isn't clear.
> It's possibly a firmware bug. For now, at least, refactor the check to
> be for DT based systems only.
>
> Note that the original implementation leaked a refcount which is now
> correctly handled.
>
> Fixes: 6fffbc7ae137 ("PCI: Honor firmware's device disabled status")
> Link: https://lore.kernel.org/all/m2fs9lgndw.fsf@gmail.com/
> Reported-by: Donald Hunter <donald.hunter@gmail.com>
> Cc: Binbin Zhou <zhoubinbin@loongson.cn>
> Cc: Liu Peibao <liupeibao@loongson.cn>
> Cc: Huacai Chen <chenhuacai@loongson.cn>
> Signed-off-by: Rob Herring <robh@kernel.org>
Applied to for-linus for (hopefully) v6.3. I added:
[bhelgaas: Per ACPI r6.5, sec 6.3.7, for devices on an enumerable
bus, _STA must return with bit[0] ("device is present") set]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217317
It would be really great if anybody who has seen this issue could test
and report whether this patch solves it.
> ---
> drivers/pci/of.c | 30 ++++++++++++++++++++++++------
> drivers/pci/pci.h | 4 ++--
> drivers/pci/probe.c | 8 ++++----
> 3 files changed, 30 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index 196834ed44fe..4c2ef2e28fb5 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -16,14 +16,32 @@
> #include "pci.h"
>
> #ifdef CONFIG_PCI
> -void pci_set_of_node(struct pci_dev *dev)
> +/**
> + * pci_set_of_node - Find and set device's DT device_node
> + * @dev: the PCI device structure to fill
> + *
> + * Returns 0 on success with of_node set or when no device is described in the
> + * DT. Returns -ENODEV if the device is present, but disabled in the DT.
> + */
> +int pci_set_of_node(struct pci_dev *dev)
> {
> + struct device_node *node;
> +
> if (!dev->bus->dev.of_node)
> - return;
> - dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
> - dev->devfn);
> - if (dev->dev.of_node)
> - dev->dev.fwnode = &dev->dev.of_node->fwnode;
> + return 0;
> +
> + node = of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
> + if (!node)
> + return 0;
> +
> + if (!of_device_is_available(node)) {
> + of_node_put(node);
> + return -ENODEV;
> + }
> +
> + dev->dev.of_node = node;
> + dev->dev.fwnode = &node->fwnode;
> + return 0;
> }
>
> void pci_release_of_node(struct pci_dev *dev)
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index d2c08670a20e..2b48a0aa8008 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -624,7 +624,7 @@ int of_pci_get_max_link_speed(struct device_node *node);
> u32 of_pci_get_slot_power_limit(struct device_node *node,
> u8 *slot_power_limit_value,
> u8 *slot_power_limit_scale);
> -void pci_set_of_node(struct pci_dev *dev);
> +int pci_set_of_node(struct pci_dev *dev);
> void pci_release_of_node(struct pci_dev *dev);
> void pci_set_bus_of_node(struct pci_bus *bus);
> void pci_release_bus_of_node(struct pci_bus *bus);
> @@ -662,7 +662,7 @@ of_pci_get_slot_power_limit(struct device_node *node,
> return 0;
> }
>
> -static inline void pci_set_of_node(struct pci_dev *dev) { }
> +static inline int pci_set_of_node(struct pci_dev *dev) { return 0; }
> static inline void pci_release_of_node(struct pci_dev *dev) { }
> static inline void pci_set_bus_of_node(struct pci_bus *bus) { }
> static inline void pci_release_bus_of_node(struct pci_bus *bus) { }
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index a3f68b6ba6ac..f96fa83f2627 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1826,7 +1826,7 @@ int pci_setup_device(struct pci_dev *dev)
> u32 class;
> u16 cmd;
> u8 hdr_type;
> - int pos = 0;
> + int err, pos = 0;
> struct pci_bus_region region;
> struct resource *res;
>
> @@ -1840,10 +1840,10 @@ int pci_setup_device(struct pci_dev *dev)
> dev->error_state = pci_channel_io_normal;
> set_pcie_port_type(dev);
>
> - pci_set_of_node(dev);
> + err = pci_set_of_node(dev);
> + if (err)
> + return err;
> pci_set_acpi_fwnode(dev);
> - if (dev->dev.fwnode && !fwnode_device_is_available(dev->dev.fwnode))
> - return -ENODEV;
>
> pci_dev_assign_slot(dev);
>
> --
> 2.39.2
>
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