lkml.org 
[lkml]   [2022]   [Aug]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2 net-next] net: ethernet: ti: davinci_mdio: Add workaround for errata i2329
    > sh_eth is not configured for autosuspend and uses only pm_runtime_put().

    I don't know the runtime power management code very well. We should
    probably ask somebody how does. However:

    https://elixir.bootlin.com/linux/latest/source/drivers/base/power/runtime.c#L168

    This suggests it should be safe to perform an auto suspend on a device
    which is not configured for auto suspend. To me, it looks like is
    should directly suspend.

    Devices are in a tree. If you suspend a leaf, you can walk up the tree
    and suspend its parent as well, if it is not needed. Similarly, if you
    wake a leaf, you need its parents awake as well, so you need to walk
    up the tree and wake them. In order for this to work reliably, i
    expect runtime PM to be very tolerant. If a device is not configured
    for runtime PM, actions should be a NOP. If it is not configured for
    auto suspend, and you ask it to auto suspend, to me, it would make
    sense for it to immediately suspend, etc.

    > Please provide your views on this. Your inputs on the next course of action
    > would be helpful.

    I would suggest you talk to somebody who knows about runtime PM.

    Andrew

    \
     
     \ /
      Last update: 2022-08-12 17:55    [W:2.233 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site