Re: [PATCH] net: phy: add suspend_halted module param

From: Sebastian Hesselbarth
Date: Tue Feb 25 2014 - 17:39:12 EST


On 02/24/2014 08:15 PM, Andrew Lunn wrote:
On Sun, Feb 23, 2014 at 05:58:39PM +0100, Sebastian Hesselbarth wrote:
commit 1211ce53077164e0d34641d0ca5fb4d4a7574498
("net: phy: resume/suspend PHYs on attach/detach")
introduced a feature to suspend PHYs when entering halted state.

Unfortunately, not all bootloaders properly power-up PHYs on reset
and fail to access ethernet because the PHY is still powered down.

Therefore, we add a boolean module parameter suspend_halted with
default value of true. Disabling that parameter prevents PHYs from
being suspended when entering halted state.

Am i doing something silly here?

root@qnap:/sys/module/libphy/parameters# cat suspend_halted
Y
root@qnap:/sys/module/libphy/parameters# echo N > suspend_halted
root@qnap:/sys/module/libphy/parameters# cat suspend_halted
N
root@qnap:/sys/module/libphy/parameters# reboot

Just to be sure, can you ifconfig up the interface before reboot?
The PHY could already be powered-down, if the interface is down.

...
...

Net: egiga0 [PRIME]
Hit any key to stop autoboot: 0
Send Cmd : 0x68 to UART1
egiga0 no link
Using egiga0 device
TFTP from server 10.0.0.1; our IP address is 10.0.0.2
Filename 'uImage-qnap'.
Load address: 0x800000
Loading: T T

Does not seem to work.

I tested the patch on Topkick (w/ 88E1318S, 0x0141 0x0e90) which
bootloader is also affected.

Both, libphy.suspend_halted=0 as kernel boot parameter and sysfs
procedure above successfully prevent the PHY from being powered
down. After reboot, u-boot tftpboot works as expected.

Sebastian

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