On Mon, Oct 07, 2024 at 11:24:46AM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
>
> Old device trees for some platforms already define wifi nodes for the WCN
> family of chips since before power sequencing was added upstream.
>
> These nodes don't consume the regulator outputs from the PMU and if we
> allow this driver to bind to one of such "incomplete" nodes, we'll see
> a kernel log error about the infinite probe deferral.
>
> Let's extend the driver by adding a platform data struct matched against
> the compatible. This struct will now contain the pwrseq target string as
> well as a validation function called right after entering probe(). For
> Qualcomm WCN models, we'll check the existence of the regulator supply
> property that indicates the DT is already using power sequencing and
> return -ENODEV if it's not there, indicating to the driver model that
> the device should not be bound to the pwrctl driver.
>
> Fixes: 6140d185a43d ("PCI/pwrctl: Add a PCI power control driver for power sequenced devices")
> Reported-by: Johan Hovold <johan@xxxxxxxxxx>
> Closes: https://lore.kernel.org/all/Zv565olMDDGHyYVt@xxxxxxxxxxxxxxxxxxxx/
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
Applied to pci/for-linus for v6.12, thanks.
It would help me out to have a hint in the posting that this is
intended for the current release, since by default everything is for
the "next" release.
> ---
> v1 -> v2:
> - make the fix more generic, add a platform data struct matched against
> the compatible and use it to store a device-specific validation
> callback
>
> drivers/pci/pwrctl/pci-pwrctl-pwrseq.c | 55 +++++++++++++++++++++++---
> 1 file changed, 50 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c
> index a23a4312574b..e331a73a1b0c 100644
> --- a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c
> +++ b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c
> @@ -6,9 +6,9 @@
> #include <linux/device.h>
> #include <linux/mod_devicetable.h>
> #include <linux/module.h>
> -#include <linux/of.h>
> #include <linux/pci-pwrctl.h>
> #include <linux/platform_device.h>
> +#include <linux/property.h>
> #include <linux/pwrseq/consumer.h>
> #include <linux/slab.h>
> #include <linux/types.h>
> @@ -18,6 +18,40 @@ struct pci_pwrctl_pwrseq_data {
> struct pwrseq_desc *pwrseq;
> };
>
> +struct pci_pwrctl_pwrseq_pdata {
> + const char *target;
> + /*
> + * Called before doing anything else to perform device-specific
> + * verification between requesting the power sequencing handle.
> + */
> + int (*validate_device)(struct device *dev);
> +};
> +
> +static int pci_pwrctl_pwrseq_qcm_wcn_validate_device(struct device *dev)
> +{
> + /*
> + * Old device trees for some platforms already define wifi nodes for
> + * the WCN family of chips since before power sequencing was added
> + * upstream.
> + *
> + * These nodes don't consume the regulator outputs from the PMU and
> + * if we allow this driver to bind to one of such "incomplete" nodes,
> + * we'll see a kernel log error about the indefinite probe deferral.
> + *
> + * Let's check the existence of the regulator supply that exists on all
> + * WCN models before moving forward.
> + */
> + if (!device_property_present(dev, "vddaon-supply"))
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static const struct pci_pwrctl_pwrseq_pdata pci_pwrctl_pwrseq_qcom_wcn_pdata = {
> + .target = "wlan",
> + .validate_device = pci_pwrctl_pwrseq_qcm_wcn_validate_device,
> +};
> +
> static void devm_pci_pwrctl_pwrseq_power_off(void *data)
> {
> struct pwrseq_desc *pwrseq = data;
> @@ -27,15 +61,26 @@ static void devm_pci_pwrctl_pwrseq_power_off(void *data)
>
> static int pci_pwrctl_pwrseq_probe(struct platform_device *pdev)
> {
> + const struct pci_pwrctl_pwrseq_pdata *pdata;
> struct pci_pwrctl_pwrseq_data *data;
> struct device *dev = &pdev->dev;
> int ret;
>
> + pdata = device_get_match_data(dev);
> + if (!pdata || !pdata->target)
> + return -EINVAL;
> +
> + if (pdata->validate_device) {
> + ret = pdata->validate_device(dev);
> + if (ret)
> + return ret;
> + }
> +
> data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> if (!data)
> return -ENOMEM;
>
> - data->pwrseq = devm_pwrseq_get(dev, of_device_get_match_data(dev));
> + data->pwrseq = devm_pwrseq_get(dev, pdata->target);
> if (IS_ERR(data->pwrseq))
> return dev_err_probe(dev, PTR_ERR(data->pwrseq),
> "Failed to get the power sequencer\n");
> @@ -64,17 +109,17 @@ static const struct of_device_id pci_pwrctl_pwrseq_of_match[] = {
> {
> /* ATH11K in QCA6390 package. */
> .compatible = "pci17cb,1101",
> - .data = "wlan",
> + .data = &pci_pwrctl_pwrseq_qcom_wcn_pdata,
> },
> {
> /* ATH11K in WCN6855 package. */
> .compatible = "pci17cb,1103",
> - .data = "wlan",
> + .data = &pci_pwrctl_pwrseq_qcom_wcn_pdata,
> },
> {
> /* ATH12K in WCN7850 package. */
> .compatible = "pci17cb,1107",
> - .data = "wlan",
> + .data = &pci_pwrctl_pwrseq_qcom_wcn_pdata,
> },
> { }
> };
> --
> 2.30.2
>
