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Message-ID: <d17b696c81a57fb857b54a8c05e121be1cfc47fa.camel@redhat.com>
Subject: Re: [PATCH 1/2] net: usb: ax88179_178a: fix failed operations
 during ax88179_reset
From:   Paolo Abeni <pabeni@redhat.com>
To:     Jose Ignacio Tornos Martinez <jtornosm@redhat.com>,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        linux-usb@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     weihao.bj@ieisystem.com
Date:   Thu, 16 Nov 2023 10:37:55 +0100
In-Reply-To: <20231114125111.313229-2-jtornosm@redhat.com>
References: <20231114125111.313229-1-jtornosm@redhat.com>
         <20231114125111.313229-2-jtornosm@redhat.com>
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On Tue, 2023-11-14 at 13:50 +0100, Jose Ignacio Tornos Martinez wrote:
> Using generic ASIX Electronics Corp. AX88179 Gigabit Ethernet device,
> the following test cycle has been implemented:
>     - power on
>     - check logs
>     - shutdown
>     - after detecting the system shutdown, disconnect power
>     - after approximately 60 seconds of sleep, power is restored
> Running some cycles, sometimes error logs like this appear:
>     kernel: ax88179_178a 2-9:1.0 (unnamed net_device) (uninitialized): Fa=
iled to write reg index 0x0001: -19
>     kernel: ax88179_178a 2-9:1.0 (unnamed net_device) (uninitialized): Fa=
iled to read reg index 0x0001: -19
>     ...
> These failed operation are happening during ax88179_reset execution, so
> the initialization could not be correct.
>=20
> In order to avoid this, we need to increase the delay after reset and
> clock initial operations. By using these larger values, many cycles
> have been run and no failed operations appear.
>=20
> Reported-by: Herb Wei <weihao.bj@ieisystem.com>
> Tested-by: Herb Wei <weihao.bj@ieisystem.com>
> Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

We need at least a suitable Fixes tag

> ---
>  drivers/net/usb/ax88179_178a.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>=20
> diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178=
a.c
> index aff39bf3161d..4ea0e155bb0d 100644
> --- a/drivers/net/usb/ax88179_178a.c
> +++ b/drivers/net/usb/ax88179_178a.c
> @@ -1583,11 +1583,11 @@ static int ax88179_reset(struct usbnet *dev)
> =20
>  	*tmp16 =3D AX_PHYPWR_RSTCTL_IPRL;
>  	ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_PHYPWR_RSTCTL, 2, 2, tmp16);
> -	msleep(200);
> +	msleep(500);

Do you know if there is some status register you can query for 'reset
completed'? or some official documentation you can quote for the above
delay?

Thanks!

Paolo