From: Niklas Söderlund <niklas.soderlund+rene...@ragnatech.se> Date: Tue, 1 Aug 2017 12:14:35 +0200
> WoL is enabled in the suspend callback by setting MagicPacket detection > and disabling all interrupts expect MagicPacket. In the resume path the > driver needs to reset the hardware to rearm the WoL logic, this prevents > the driver from simply restoring the registers and to take advantage of > that ravb was not suspended to reduce resume time. To reset the > hardware the driver closes the device, sets it in reset mode and reopens > the device just like it would do in a normal suspend/resume scenario > without WoL enabled, but it both closes and opens the device in the > resume callback since the device needs to be reset for WoL to work. > > One quirk needed for WoL is that the module clock needs to be prevented > from being switched off by Runtime PM. To keep the clock alive the > suspend callback need to call clk_enable() directly to increase the > usage count of the clock. Then when Runtime PM decreases the clock usage > count it won't reach 0 and be switched off. > > Changes since v2 > - Only do the clock dance to workaround PSCI sleep when resuming if WoL > is enabled. This was a bug in v2 which resulted in a WARN if resuming > from PSCI sleep with WoL disabled, thanks Sergei for pointing this > out! > - Break out clock dance workaround in separate patch to make it easier > to revert once a fix is upstream for the clock driver as suggested by > Sergei. > > Changes since v1 > - Fix issue where device would fail to resume from PSCI suspend if WoL > was enabled, reported by Geert. The fault was that the clock driver > thinks the clock is on, but PSCI have disabled it, added workaround > for this in ravb driver which can be removed once the clock driver is > aware of the PSCI behavior. > - Only try to restore from wol wake up if netif is running, since this > is a condition to enable wol in the first place this was a bug in v1. Series applied, thanks.
