diff options
Diffstat (limited to 'drivers/net/usb/asix_devices.c')
| -rw-r--r-- | drivers/net/usb/asix_devices.c | 41 |
1 files changed, 38 insertions, 3 deletions
diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c index 792ddda1ad49..232bbd79a4de 100644 --- a/drivers/net/usb/asix_devices.c +++ b/drivers/net/usb/asix_devices.c @@ -230,7 +230,9 @@ static int ax88172_bind(struct usbnet *dev, struct usb_interface *intf) int i; unsigned long gpio_bits = dev->driver_info->data; - usbnet_get_endpoints(dev,intf); + ret = usbnet_get_endpoints(dev, intf); + if (ret) + goto out; /* Toggle the GPIOs in a manufacturer/model specific way */ for (i = 2; i >= 0; i--) { @@ -625,6 +627,21 @@ static void ax88772_suspend(struct usbnet *dev) asix_read_medium_status(dev, 1)); } +/* Notes on PM callbacks and locking context: + * + * - asix_suspend()/asix_resume() are invoked for both runtime PM and + * system-wide suspend/resume. For struct usb_driver the ->resume() + * callback does not receive pm_message_t, so the resume type cannot + * be distinguished here. + * + * - The MAC driver must hold RTNL when calling phylink interfaces such as + * phylink_suspend()/resume(). Those calls will also perform MDIO I/O. + * + * - Taking RTNL and doing MDIO from a runtime-PM resume callback (while + * the USB PM lock is held) is fragile. Since autosuspend brings no + * measurable power saving here, we block it by holding a PM usage + * reference in ax88772_bind(). + */ static int asix_suspend(struct usb_interface *intf, pm_message_t message) { struct usbnet *dev = usb_get_intfdata(intf); @@ -833,7 +850,9 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf) dev->driver_priv = priv; - usbnet_get_endpoints(dev, intf); + ret = usbnet_get_endpoints(dev, intf); + if (ret) + return ret; /* Maybe the boot loader passed the MAC address via device tree */ if (!eth_platform_get_mac_address(&dev->udev->dev, buf)) { @@ -919,6 +938,13 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf) if (ret) goto initphy_err; + /* Keep this interface runtime-PM active by taking a usage ref. + * Prevents runtime suspend while bound and avoids resume paths + * that could deadlock (autoresume under RTNL while USB PM lock + * is held, phylink/MDIO wants RTNL). + */ + pm_runtime_get_noresume(&intf->dev); + return 0; initphy_err: @@ -948,6 +974,8 @@ static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf) phylink_destroy(priv->phylink); ax88772_mdio_unregister(priv); asix_rx_fixup_common_free(dev->driver_priv); + /* Drop the PM usage ref taken in bind() */ + pm_runtime_put(&intf->dev); } static void ax88178_unbind(struct usbnet *dev, struct usb_interface *intf) @@ -1257,7 +1285,9 @@ static int ax88178_bind(struct usbnet *dev, struct usb_interface *intf) int ret; u8 buf[ETH_ALEN] = {0}; - usbnet_get_endpoints(dev,intf); + ret = usbnet_get_endpoints(dev, intf); + if (ret) + return ret; /* Get the MAC address */ ret = asix_read_cmd(dev, AX_CMD_READ_NODE_ID, 0, 0, ETH_ALEN, buf, 0); @@ -1600,6 +1630,11 @@ static struct usb_driver asix_driver = { .resume = asix_resume, .reset_resume = asix_resume, .disconnect = usbnet_disconnect, + /* usbnet enables autosuspend by default (supports_autosuspend=1). + * We keep runtime-PM active for AX88772* by taking a PM usage + * reference in ax88772_bind() (pm_runtime_get_noresume()) and + * dropping it in unbind(), which effectively blocks autosuspend. + */ .supports_autosuspend = 1, .disable_hub_initiated_lpm = 1, }; |