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? -- 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/
