On 24/04/15 10:25, Sergei Shtylyov wrote: > On 04/24/2015 06:56 PM, Florian Fainelli wrote: > >>>> 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, > > It is not (as we have discussed recently) -- cancel_work_sync() may > sleep.
True, but that does not invalidate my comment, I meant to write that this is the only function that you *might* potentially want to call from interrupt context, and yet it does not trigger low-level I/O accesses to the underlying MDIO bus, but instead uses the PHY library state machine workqueue to do that. Thanks for the reminder though, that needs fixing ;) -- 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/
