On 24/04/15 09:01, David Miller wrote: > From: Florian Fainelli <f.faine...@gmail.com> > Date: Fri, 24 Apr 2015 08:56:34 -0700 > >> On 24/04/15 08:04, David Miller wrote: >>> From: Vivien Didelot <vivien.dide...@savoirfairelinux.com> >>> Date: Wed, 22 Apr 2015 13:06:54 -0400 >>> >>>> Some systems using mdio-gpio may use gpio on message based busses, which >>>> require sleeping (e.g. gpio from an I2C I/O expander). >>>> >>>> Since this driver does not use IRQ handler, it is safe to use the >>>> _cansleep suffixed gpio accessors. >>>> >>>> Signed-off-by: Vivien Didelot <vivien.dide...@savoirfairelinux.com> >>> >>> Since this is down underneath the layer of an MII bus, you cannot >>> universally say that these routines are always called in a sleepable >>> context. >>> >>> The PHY layer, and the driver itself above that, might call these >>> routines from timers, interruptes etc. >> >> The PHY library calls these routines from its state machine workqueue >> for that reason, or from process context (when invoked via ethtool >> ioctl). The only special case is phy_mac_interrupt() which is callable >> from interrupt context, but schedules the state machine workqueue anyway >> to circumvent the "in-interrupt" context. >> >> If we were not doing that, there would be a number of things broken, for >> instance the per-MDIO bus mutex would not protect us from anything. > > Does the link state polling timer use a workqueue in this manner as > well?
Yes, the state machine re-schedules its own delayed workqueue at the end of its state processing, no timer/hrtimer is used. -- Florian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
