[PATCH v2] platform/chrome: cros_usbpd_notify: defer probe when parent EC driver isn't ready

[PATCH v2] platform/chrome: cros_usbpd_notify: defer probe when parent EC driver isn't ready

[Jameson Thies]

The cros-usbpd-notify-acpi probe currently does not exit when it fails
to get a pointer to the ChromeOS EC device. It is expected behavior on
older devices, where GOOG0004 is not a parent of GOOG0003.

Update the cros-usbpd-notify-acpi probe to check for a GOOG0004 parent
fwnode. If the device has correct device hierarchy and fails to get an
EC device pointer, defer the probe function.

Signed-off-by: Jameson Thies <jthies@google.com>
---
 drivers/platform/chrome/cros_usbpd_notify.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/chrome/cros_usbpd_notify.c b/drivers/platform/chrome/cros_usbpd_notify.c
index 313d2bcd577b..c90174360004 100644
--- a/drivers/platform/chrome/cros_usbpd_notify.c
+++ b/drivers/platform/chrome/cros_usbpd_notify.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/fwnode.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/platform_data/cros_ec_proto.h>
@@ -15,6 +16,7 @@
 #define DRV_NAME "cros-usbpd-notify"
 #define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi"
 #define ACPI_DRV_NAME "GOOG0003"
+#define CREC_DRV_NAME "GOOG0004"
 
 static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);
 
@@ -98,8 +100,9 @@ static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
 {
 	struct cros_usbpd_notify_data *pdnotify;
 	struct device *dev = &pdev->dev;
-	struct acpi_device *adev;
+	struct acpi_device *adev, *parent_adev;
 	struct cros_ec_device *ec_dev;
+	struct fwnode_handle *parent_fwnode;
 	acpi_status status;
 
 	adev = ACPI_COMPANION(dev);
@@ -114,8 +117,18 @@ static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
 		/*
 		 * We continue even for older devices which don't have the
 		 * correct device heirarchy, namely, GOOG0003 is a child
-		 * of GOOG0004.
+		 * of GOOG0004. If GOOG0003 is a child of GOOG0004 and we
+		 * can't get a pointer to the Chrome EC device, defer the
+		 * probe function.
 		 */
+		parent_fwnode = fwnode_get_parent(dev->fwnode);
+		if (parent_fwnode) {
+			parent_adev = to_acpi_device_node(parent_fwnode);
+			if (parent_adev &&
+			    acpi_dev_hid_match(parent_adev, CREC_DRV_NAME)) {
+				return -EPROBE_DEFER;
+			}
+		}
 		dev_warn(dev, "Couldn't get Chrome EC device pointer.\n");
 	}
 

base-commit: 48633acccf38d706d7b368400647bb9db9caf1ae
-- 
2.51.0.618.g983fd99d29-goog

Re: [PATCH v2] platform/chrome: cros_usbpd_notify: defer probe when parent EC driver isn't ready

[Tzung-Bi Shih]

On Tue, Oct 07, 2025 at 12:40:43AM +0000, Jameson Thies wrote:
> The cros-usbpd-notify-acpi probe currently does not exit when it fails
> to get a pointer to the ChromeOS EC device. It is expected behavior on
> older devices, where GOOG0004 is not a parent of GOOG0003.
> 
> Update the cros-usbpd-notify-acpi probe to check for a GOOG0004 parent
> fwnode. If the device has correct device hierarchy and fails to get an
> EC device pointer, defer the probe function.

I plan to queue the patch after rebasing to -rc1 if no objections and also
collect Benson's R-b tag from v1.

Re: [PATCH v2] platform/chrome: cros_usbpd_notify: defer probe when parent EC driver isn't ready

[Benson Leung]

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Hi Jameson,

Minor nit, please provide a summary of differences since v1 below the --- in
the future.

On Tue, Oct 07, 2025 at 12:40:43AM +0000, Jameson Thies wrote:
> The cros-usbpd-notify-acpi probe currently does not exit when it fails
> to get a pointer to the ChromeOS EC device. It is expected behavior on
> older devices, where GOOG0004 is not a parent of GOOG0003.
> 
> Update the cros-usbpd-notify-acpi probe to check for a GOOG0004 parent
> fwnode. If the device has correct device hierarchy and fails to get an
> EC device pointer, defer the probe function.
> 
> Signed-off-by: Jameson Thies <jthies@google.com>

Reviewed-by: Benson Leung <bleung@chromium.org>


> ---
>  drivers/platform/chrome/cros_usbpd_notify.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/platform/chrome/cros_usbpd_notify.c b/drivers/platform/chrome/cros_usbpd_notify.c
> index 313d2bcd577b..c90174360004 100644
> --- a/drivers/platform/chrome/cros_usbpd_notify.c
> +++ b/drivers/platform/chrome/cros_usbpd_notify.c
> @@ -6,6 +6,7 @@
>   */
>  
>  #include <linux/acpi.h>
> +#include <linux/fwnode.h>
>  #include <linux/mod_devicetable.h>
>  #include <linux/module.h>
>  #include <linux/platform_data/cros_ec_proto.h>
> @@ -15,6 +16,7 @@
>  #define DRV_NAME "cros-usbpd-notify"
>  #define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi"
>  #define ACPI_DRV_NAME "GOOG0003"
> +#define CREC_DRV_NAME "GOOG0004"
>  
>  static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);
>  
> @@ -98,8 +100,9 @@ static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
>  {
>  	struct cros_usbpd_notify_data *pdnotify;
>  	struct device *dev = &pdev->dev;
> -	struct acpi_device *adev;
> +	struct acpi_device *adev, *parent_adev;
>  	struct cros_ec_device *ec_dev;
> +	struct fwnode_handle *parent_fwnode;
>  	acpi_status status;
>  
>  	adev = ACPI_COMPANION(dev);
> @@ -114,8 +117,18 @@ static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
>  		/*
>  		 * We continue even for older devices which don't have the
>  		 * correct device heirarchy, namely, GOOG0003 is a child
> -		 * of GOOG0004.
> +		 * of GOOG0004. If GOOG0003 is a child of GOOG0004 and we
> +		 * can't get a pointer to the Chrome EC device, defer the
> +		 * probe function.
>  		 */
> +		parent_fwnode = fwnode_get_parent(dev->fwnode);
> +		if (parent_fwnode) {
> +			parent_adev = to_acpi_device_node(parent_fwnode);
> +			if (parent_adev &&
> +			    acpi_dev_hid_match(parent_adev, CREC_DRV_NAME)) {
> +				return -EPROBE_DEFER;
> +			}
> +		}
>  		dev_warn(dev, "Couldn't get Chrome EC device pointer.\n");
>  	}
>  
> 
> base-commit: 48633acccf38d706d7b368400647bb9db9caf1ae
> -- 
> 2.51.0.618.g983fd99d29-goog
> 

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Re: [PATCH v2] platform/chrome: cros_usbpd_notify: defer probe when parent EC driver isn't ready

[Tzung-Bi Shih]

On Tue, Oct 07, 2025 at 12:40:43AM +0000, Jameson Thies wrote:
> The cros-usbpd-notify-acpi probe currently does not exit when it fails
> to get a pointer to the ChromeOS EC device. It is expected behavior on
> older devices, where GOOG0004 is not a parent of GOOG0003.
> 
> Update the cros-usbpd-notify-acpi probe to check for a GOOG0004 parent
> fwnode. If the device has correct device hierarchy and fails to get an
> EC device pointer, defer the probe function.
>
> [...]

Applied to

    https://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux.git for-next

[1/1] platform/chrome: cros_usbpd_notify: defer probe when parent EC driver isn't ready
      commit: e4ee0bb077cd7d70207647a0106f6ea6a74c2636

Thanks!