[PATCH] PCI: keystone: fix crash with deferred probe

Jisheng Zhang
2015-11-23T11:22:09Z

Dear Sekhar,

On Fri, 20 Nov 2015 16:47:02 +0530
Sekhar Nori wrote:

> Drop __init annotations for functions called during
> probe of keystone PCIe host.
>
> This fixes kernel crashes seen because of init data
> reclamation if the driver defer probes because of
> phy unavailability.
>
> While at it, drop the useless __refdata annotation
> to driver structure. If its really needed, it should
> be added back with a comment explaining why.
>
> Signed-off-by: Sekhar Nori <nsekhar@ti.com>
> ---
> drivers/pci/host/pci-keystone-dw.c | 2 +-
> drivers/pci/host/pci-keystone.c | 6 +++---
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/host/pci-keystone-dw.c b/drivers/pci/host/pci-keystone-dw.c
> index ed34c9520a02..47ddbcce53ca 100644
> --- a/drivers/pci/host/pci-keystone-dw.c
> +++ b/drivers/pci/host/pci-keystone-dw.c
> @@ -469,7 +469,7 @@ void ks_dw_pcie_initiate_link_train(struct keystone_pcie *ks_pcie)
> * and call dw_pcie_v3_65_host_init() API to initialize the Keystone
> * PCI host controller.
> */
> -int __init ks_dw_pcie_host_init(struct keystone_pcie *ks_pcie,
> +int ks_dw_pcie_host_init(struct keystone_pcie *ks_pcie,
> struct device_node *msi_intc_np)

when trying to add berlin pcie support and came up one patch

http://lists.infradead.org/pipermail/linux-arm-kernel/2015-November/384575.html

when build testing, I also realized this issue, but keystone relies on
hook_fault_code() which is will be freed after boot, so your patch isn't
completed.

And from the keystone driver implementation, it seems assume the driver won't
be defer probed.

Thanks

> {
> struct pcie_port *pp = &ks_pcie->pp;
> diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
> index 0aa81bd3de12..593a58834c7d 100644
> --- a/drivers/pci/host/pci-keystone.c
> +++ b/drivers/pci/host/pci-keystone.c
> @@ -291,7 +291,7 @@ static struct pcie_host_ops keystone_pcie_host_ops = {
> .scan_bus = ks_dw_pcie_v3_65_scan_bus,
> };
>
> -static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
> +static int ks_add_pcie_port(struct keystone_pcie *ks_pcie,
> struct platform_device *pdev)
> {
> struct pcie_port *pp = &ks_pcie->pp;
> @@ -340,7 +340,7 @@ static int __exit ks_pcie_remove(struct platform_device *pdev)
> return 0;
> }
>
> -static int __init ks_pcie_probe(struct platform_device *pdev)
> +static int ks_pcie_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct keystone_pcie *ks_pcie;
> @@ -396,7 +396,7 @@ fail_clk:
> return ret;
> }
>
> -static struct platform_driver ks_pcie_driver __refdata = {
> +static struct platform_driver ks_pcie_driver = {
> .probe = ks_pcie_probe,
> .remove = __exit_p(ks_pcie_remove),
> .driver = {