Re: [PATCH 1/1] net: phylib: remove the length limitation of mii bus id

From: Dong Aisheng
Date: Tue Mar 20 2012 - 06:53:20 EST


On Tue, Mar 20, 2012 at 1:32 AM, Shawn Guo <shawn.guo@xxxxxxxxxx> wrote:
> On 20 March 2012 12:23, Dong Aisheng <b29396@xxxxxxxxxxxxx> wrote:
>> From: Dong Aisheng <dong.aisheng@xxxxxxxxxx>
>>
>> When convert to dt, the length of old mii bus id (17 bytes) is not
>> sufficent to use.
>> For example, the bus id could be 800f0000.ethernet-1:00 in DT.
>>
>> This patch removes the bus id length limitation by changing the
>> bus id to a const char pionter and user could dynamically set the
>> bus id via kasprintf function call.
>>
>> Since then no users use MII_BUS_ID_SIZE any more, just remove it.
>>
>> Signed-off-by: Dong Aisheng <dong.aisheng@xxxxxxxxxx>
>> ---
>> The simplest way may just change MII_BUS_ID_SIZE to a more bigger size,
>> but i'm not sure that's gonna be accepted.
>
> The simplest fix has been applied on -next tree as below.
>
Oh, i missed it, seems my patch covers that change.
But that patch only fixed wrong phy_name buffer length issue.
My patch is totally remove the length limitation of bus id and phy_name
or the bus id name will be truncated if it's longer than MII_BUS_ID_SIZE
which is not a comfortable limitation.

> commit a7ed07d51c8abdb407be454c6cb6cfad613759d9
> Author: Richard Zhao <richard.zhao@xxxxxxxxxx>
> Date:   Sun Jan 29 22:08:12 2012 +0000
>
>    net: fec: correct phy_name buffer length when init phy_name
>
>    Fix the bug that we got wrong phy_name on imx6q sabrelite board.
>    snprintf used wrong length of phy_name.
>    phy_name length is MII_BUS_ID_SIZE + 3 rather not MII_BUS_ID_SIZE.
>    I change it to sizeof(phy_name).
>
>    Signed-off-by: Richard Zhao <richard.zhao@xxxxxxxxxx>
>    Acked-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
>    Acked-by: Florian Fainelli <florian@xxxxxxxxxxx>
>    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
>
> diff --git a/drivers/net/ethernet/freescale/fec.c
> b/drivers/net/ethernet/freescale/fec.c
> index 7b25e9c..1c7aad8 100644
> --- a/drivers/net/ethernet/freescale/fec.c
> +++ b/drivers/net/ethernet/freescale/fec.c
> @@ -990,7 +990,7 @@ static int fec_enet_mii_probe(struct net_device *ndev)
>                phy_id = 0;
>        }
>
> -       snprintf(phy_name, MII_BUS_ID_SIZE, PHY_ID_FMT, mdio_bus_id, phy_id);
> +       snprintf(phy_name, sizeof(phy_name), PHY_ID_FMT, mdio_bus_id, phy_id);
>        phy_dev = phy_connect(ndev, phy_name, &fec_enet_adjust_link, 0,
>                              fep->phy_interface);
>        if (IS_ERR(phy_dev)) {
--
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