| Message ID | 20230706182858.761311-1-alexandru.gagniuc@hp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | r8152: Suspend USB device before shutdown when WoL is enabled | expand |
On Thu, 6 Jul 2023 18:28:58 +0000 Alexandru Gagniuc wrote: > For Wake-on-LAN to work from S5 (shutdown), the USB link must be put > in U3 state. If it is not, and the host "disappears", the chip will > no longer respond to WoL triggers. > > To resolve this, add a notifier block and register it as a reboot > notifier. When WoL is enabled, work through the usb_device struct to > get to the suspend function. Calling this function puts the link in > the correct state for WoL to function. Would be good to hear from USB experts on this one, to an outside seems like something that the bus should be doing, possibly based on some driver opt-in.. > Cc: stable@vger.kernel.org > Signed-off-by: Alexandru Gagniuc <alexandru.gagniuc@hp.com> Please add a Fixes tag - I'm guessing it dates back to Fixes: 21ff2e8976b1 ("r8152: support WOL") ?
On Fri, Jul 07, 2023 at 05:12:25PM -0700, Jakub Kicinski wrote: > On Thu, 6 Jul 2023 18:28:58 +0000 Alexandru Gagniuc wrote: > > For Wake-on-LAN to work from S5 (shutdown), the USB link must be put > > in U3 state. If it is not, and the host "disappears", the chip will > > no longer respond to WoL triggers. > > > > To resolve this, add a notifier block and register it as a reboot > > notifier. When WoL is enabled, work through the usb_device struct to > > get to the suspend function. Calling this function puts the link in > > the correct state for WoL to function. > > Would be good to hear from USB experts on this one, to an outside seems > like something that the bus should be doing, possibly based on some > driver opt-in.. The USB spec does not include any discussion of what things should be done when the system is turned off -- it doesn't even really acknowledge the existence of different system-wide power states. As a result, the USB subsystem never developed any support for power-off callbacks or anything else of the sort. Of course, this kind of thing can always be added. But I don't think there's any way to distinguish (at the USB level) between wakeup from S5-off and wakeup from any other low-power system state. And the PM part of the device model doesn't have multiple types of "enable-wakeup" flags -- either a device is enabled for wakeup or it isn't. Alan Stern
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index 0999a58ca9d2..5623ca5c9142 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -20,6 +20,7 @@ #include <net/ip6_checksum.h> #include <uapi/linux/mdio.h> #include <linux/mdio.h> +#include <linux/reboot.h> #include <linux/usb/cdc.h> #include <linux/suspend.h> #include <linux/atomic.h> @@ -875,6 +876,7 @@ struct r8152 { struct delayed_work schedule, hw_phy_work; struct mii_if_info mii; struct mutex control; /* use for hw setting */ + struct notifier_block reboot_notifier; #ifdef CONFIG_PM_SLEEP struct notifier_block pm_notifier; #endif @@ -9609,6 +9611,25 @@ static bool rtl8152_supports_lenovo_macpassthru(struct usb_device *udev) return 0; } +/* Suspend realtek chip before system shutdown + * + * For Wake-on-LAN to work from S5, the USB link must be put in U3 state. If + * the host otherwise "disappears", the chip will not respond to WoL triggers. + */ +static int rtl8152_notify(struct notifier_block *nb, unsigned long code, + void *unused) +{ + struct r8152 *tp = container_of(nb, struct r8152, reboot_notifier); + struct device *dev = &tp->udev->dev; + + if (code == SYS_POWER_OFF) { + if (tp->saved_wolopts && dev->type->pm->suspend) + dev->type->pm->suspend(dev); + } + + return NOTIFY_DONE; +} + static int rtl8152_probe(struct usb_interface *intf, const struct usb_device_id *id) { @@ -9791,6 +9812,9 @@ static int rtl8152_probe(struct usb_interface *intf, else device_set_wakeup_enable(&udev->dev, false); + tp->reboot_notifier.notifier_call = rtl8152_notify; + register_reboot_notifier(&tp->reboot_notifier); + netif_info(tp, probe, netdev, "%s\n", DRIVER_VERSION); return 0; @@ -9811,6 +9835,7 @@ static void rtl8152_disconnect(struct usb_interface *intf) if (tp) { rtl_set_unplug(tp); + unregister_reboot_notifier(&tp->reboot_notifier); unregister_netdev(tp->netdev); tasklet_kill(&tp->tx_tl); cancel_delayed_work_sync(&tp->hw_phy_work);
For Wake-on-LAN to work from S5 (shutdown), the USB link must be put in U3 state. If it is not, and the host "disappears", the chip will no longer respond to WoL triggers. To resolve this, add a notifier block and register it as a reboot notifier. When WoL is enabled, work through the usb_device struct to get to the suspend function. Calling this function puts the link in the correct state for WoL to function. Cc: stable@vger.kernel.org Signed-off-by: Alexandru Gagniuc <alexandru.gagniuc@hp.com> --- drivers/net/usb/r8152.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)