[PATCH] net: stmmac: dwmac-rk: fix unbalanced pm_runtime_enable warnings

[Michael Riesch]

Hi ChenYu,

On 8/29/21 7:48 PM, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, Aug 23, 2021 at 10:39 PM Michael Riesch
> <michael.riesch at wolfvision.net> wrote:
>>
>> This reverts commit 2c896fb02e7f65299646f295a007bda043e0f382
>> "net: stmmac: dwmac-rk: add pd_gmac support for rk3399" and fixes
>> unbalanced pm_runtime_enable warnings.
>>
>> In the commit to be reverted, support for power management was
>> introduced to the Rockchip glue code. Later, power management support
>> was introduced to the stmmac core code, resulting in multiple
>> invocations of pm_runtime_{enable,disable,get_sync,put_sync}.
>>
>> The multiple invocations happen in rk_gmac_powerup and
>> stmmac_{dvr_probe, resume} as well as in rk_gmac_powerdown and
>> stmmac_{dvr_remove, suspend}, respectively, which are always called
>> in conjunction.
>>
>> Signed-off-by: Michael Riesch <michael.riesch at wolfvision.net>
> 
> I just found that Ethernet stopped working on my RK3399 devices,
> and I bisected it down to this patch.

Oh dear. First patch in a kernel release for a while and I already break
things.

Cc: Sasha as this patch has just been applied to 5.13-stable.

> The symptom I see is no DHCP responses, either because the request
> isn't getting sent over the wire, or the response isn't getting
> received. The PHY seems to be working correctly.

Unfortunately I don't have any RK3399 hardware. Is this a custom
board/special hardware or something that is readily available in the
shops? Maybe this is a good reason to buy a RK3399 based single-board
computer :-)

I am working on the RK3568 EVB1 and have not encountered faulty
behavior. DHCP works fine and I can boot via NFS. Therefore, not sure
whether I can be much of help in this matter, but in case you want to
discuss this further please do not hesitate to contact me off-list.

> ChenYu

Best regards,
Michael