On Wed, Jun 26, 2024 at 2:38 PM Krishna chaitanya chundru
<quic_krichai@xxxxxxxxxxx> wrote:
>
> Currently the power control driver is child of pci-pci bridge driver,
> this will cause issue when suspend resume is introduced in the pwr
> control driver. If the supply is removed to the endpoint in the
> power control driver then the config space access initaited by the
> pci-pci bridge driver can cause issues like Timeouts.
>
> For this reason change the parent to controller from pci-pci bridge.
Newline before trailers please.
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> ---
> drivers/pci/bus.c | 5 +++--
> drivers/pci/pwrctl/core.c | 7 ++++++-
> 2 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
> index 3e3517567721..eedab4aabd81 100644
> --- a/drivers/pci/bus.c
> +++ b/drivers/pci/bus.c
> @@ -335,6 +335,7 @@ void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
> void pci_bus_add_device(struct pci_dev *dev)
> {
> struct device_node *dn = dev->dev.of_node;
> + struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
> int retval;
>
> /*
> @@ -356,9 +357,9 @@ void pci_bus_add_device(struct pci_dev *dev)
>
> pci_dev_assign_added(dev, true);
>
> - if (pci_is_bridge(dev)) {
> + if (pci_is_bridge(dev) && host) {
I know I told you to check the return value of pci_find_host_bridge()
in private but now after a second look I see it's just a multi-layer
wrapper around container_of() and it looks like it cannot fail so -
correct me if I'm wrong - this can be dropped after all.
> retval = of_platform_populate(dev->dev.of_node, NULL, NULL,
> - &dev->dev);
> + host->dev.parent);
> if (retval)
> pci_err(dev, "failed to populate child OF nodes (%d)\n",
> retval);
> diff --git a/drivers/pci/pwrctl/core.c b/drivers/pci/pwrctl/core.c
> index feca26ad2f6a..4c0d0f3b15f8 100644
> --- a/drivers/pci/pwrctl/core.c
> +++ b/drivers/pci/pwrctl/core.c
> @@ -10,6 +10,7 @@
> #include <linux/pci-pwrctl.h>
> #include <linux/property.h>
> #include <linux/slab.h>
New line here, please.
> +#include "../pci.h"
>
> static int pci_pwrctl_notify(struct notifier_block *nb, unsigned long action,
> void *data)
> @@ -64,18 +65,22 @@ static int pci_pwrctl_notify(struct notifier_block *nb, unsigned long action,
> */
> int pci_pwrctl_device_set_ready(struct pci_pwrctl *pwrctl)
> {
> + struct pci_bus *bus = pci_find_bus(of_get_pci_domain_nr(pwrctl->dev->parent->of_node), 0);
> int ret;
>
> if (!pwrctl->dev)
> return -ENODEV;
>
> + if (!bus)
> + return -ENODEV;
This - on the other hand - can fail, so the check if valid. Could you
assign it and then test it in a single spot for better readability?
Bart
> +
> pwrctl->nb.notifier_call = pci_pwrctl_notify;
> ret = bus_register_notifier(&pci_bus_type, &pwrctl->nb);
> if (ret)
> return ret;
>
> pci_lock_rescan_remove();
> - pci_rescan_bus(to_pci_dev(pwrctl->dev->parent)->bus);
> + pci_rescan_bus(bus);
> pci_unlock_rescan_remove();
>
> return 0;
>
> --
> 2.42.0
>
