Re: [PATCH/RFC] net: phy: device: Don't deassert the reset when register and probe

On 27.11.2018 17:44, Andrew Lunn wrote:

On Tue, Nov 27, 2018 at 12:18:20PM +0000, Yoshihiro Shimoda wrote:

quoted

Some PHY device needs edge signal of the reset, but the previous code
is impossible to achieve it like following:

 1) Kernel boots by using initramfs.
 --> No open the nic, so the provious code deasserts the reset by
     phy_device_register() and phy_probe().
 2) Kernel enters the suspend.
 --> So, keep the reset signal as deassert.
 --> On R-Car Salvator-XS board, unfortunately, the board power is
     turned off.
 3) Kernel returns from suspend.
 4) ifconfig eth0 up
 --> Then, since edge signal of the reset doesn't happen,
     it cannot link up.

Hi Yoshihiro

It sounds like you should be adding code to the suspend/resume
handling of phylib, so that it toggle the reset on resume. You cannot
just delete code like you proposed, it is going to break devices. But
adding code should be O.K.

The commit message mentions that the patch is supposed to fix some
issue on the Salvator-XS board. I found the following from a year ago
https://www.spinics.net/lists/netdev/msg457308.html
which is also about PHY reset and this board. Is there still something
open?  But as Andrew mentioned already: Just deleting code w/o
checking what it's good for and whether this could have side effects,
isn't a solution. Especially because the patch would silently remove
the call to phy_scan_fixups().

Heiner

       Andrew
.