mirror of https://github.com/torvalds/linux.git
3d3c4cd5c6
Prevent USB runtime PM (autosuspend) for AX88772* in bind.
usbnet enables runtime PM (autosuspend) by default, so disabling it via
the usb_driver flag is ineffective. On AX88772B, autosuspend shows no
measurable power saving with current driver (no link partner, admin
up/down). The ~0.453 W -> ~0.248 W drop on v6.1 comes from phylib powering
the PHY off on admin-down, not from USB autosuspend.
The real hazard is that with runtime PM enabled, ndo_open() (under RTNL)
may synchronously trigger autoresume (usb_autopm_get_interface()) into
asix_resume() while the USB PM lock is held. Resume paths then invoke
phylink/phylib and MDIO, which also expect RTNL, leading to possible
deadlocks or PM lock vs MDIO wake issues.
To avoid this, keep the device runtime-PM active by taking a usage
reference in ax88772_bind() and dropping it in unbind(). A non-zero PM
usage count blocks runtime suspend regardless of userspace policy
(.../power/control - pm_runtime_allow/forbid), making this approach
robust against sysfs overrides.
Holding a runtime-PM usage ref does not affect system-wide suspend;
system sleep/resume callbacks continue to run as before.
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| aqc111.c | ||
| aqc111.h | ||
| asix.h | ||
| asix_common.c | ||
| asix_devices.c | ||
| ax88172a.c | ||
| ax88179_178a.c | ||
| catc.c | ||
| cdc-phonet.c | ||
| cdc_eem.c | ||
| cdc_ether.c | ||
| cdc_mbim.c | ||
| cdc_ncm.c | ||
| cdc_subset.c | ||
| ch9200.c | ||
| cx82310_eth.c | ||
| dm9601.c | ||
| gl620a.c | ||
| hso.c | ||
| huawei_cdc_ncm.c | ||
| int51x1.c | ||
| ipheth.c | ||
| kalmia.c | ||
| kaweth.c | ||
| lan78xx.c | ||
| lan78xx.h | ||
| lg-vl600.c | ||
| mcs7830.c | ||
| net1080.c | ||
| pegasus.c | ||
| pegasus.h | ||
| plusb.c | ||
| qmi_wwan.c | ||
| r8152.c | ||
| r8153_ecm.c | ||
| rndis_host.c | ||
| rtl8150.c | ||
| sierra_net.c | ||
| smsc75xx.c | ||
| smsc75xx.h | ||
| smsc95xx.c | ||
| smsc95xx.h | ||
| sr9700.c | ||
| sr9700.h | ||
| sr9800.c | ||
| sr9800.h | ||
| usbnet.c | ||
| zaurus.c | ||