Am Wed, 5 Jan 2022 15:38:51 +0800
schrieb Aaron Ma <aaron.ma@xxxxxxxxxxxxx>:
> On 1/5/22 15:32, Henning Schild wrote:
> > Am Wed, 5 Jan 2022 08:23:55 +0100
> > schrieb Henning Schild <henning.schild@xxxxxxxxxxx>:
> >
> >> Hi Aaron,
> >>
> >> if this or something similar goes in, please add another patch to
> >> remove the left-over defines.
> >>
>
> Sure, I will do it.
>
> >> Am Wed, 5 Jan 2022 14:17:47 +0800
> >> schrieb Aaron Ma <aaron.ma@xxxxxxxxxxxxx>:
> >>
> >>> When plugin multiple r8152 ethernet dongles to Lenovo Docks
> >>> or USB hub, MAC passthrough address from BIOS should be
> >>> checked if it had been used to avoid using on other dongles.
> >>>
> >>> Currently builtin r8152 on Dock still can't be identified.
> >>> First detected r8152 will use the MAC passthrough address.
> >>>
> >>> Signed-off-by: Aaron Ma <aaron.ma@xxxxxxxxxxxxx>
> >>> ---
> >>> drivers/net/usb/r8152.c | 10 ++++++++++
> >>> 1 file changed, 10 insertions(+)
> >>>
> >>> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> >>> index f9877a3e83ac..77f11b3f847b 100644
> >>> --- a/drivers/net/usb/r8152.c
> >>> +++ b/drivers/net/usb/r8152.c
> >>> @@ -1605,6 +1605,7 @@ static int
> >>> vendor_mac_passthru_addr_read(struct r8152 *tp, struct sockaddr
> >>> *sa) char *mac_obj_name; acpi_object_type mac_obj_type;
> >>> int mac_strlen;
> >>> + struct net_device *ndev;
> >>>
> >>> if (tp->lenovo_macpassthru) {
> >>> mac_obj_name = "\\MACA";
> >>> @@ -1662,6 +1663,15 @@ static int
> >>> vendor_mac_passthru_addr_read(struct r8152 *tp, struct sockaddr
> >>> *sa) ret = -EINVAL; goto amacout;
> >>> }
> >>> + rcu_read_lock();
> >>> + for_each_netdev_rcu(&init_net, ndev) {
> >>> + if (strncmp(buf, ndev->dev_addr, 6) == 0) {
> >>> + rcu_read_unlock();
> >>> + goto amacout;
> >>
> >> Since the original PCI netdev will always be there, that would
> >> disable inheritance would it not?
> >> I guess a strncmp(MODULE_NAME, info->driver, strlen(MODULE_NAME))
> >> is needed as well.
> >>
>
> PCI ethernet could be a builtin one on dock since there will be TBT4
> dock.
In my X280 there is a PCI device in the laptop, always there. And its
MAC is the one found in ACPI. Did not try but i think for such devices
there would never be inheritance even if one wanted and used a Lenovo
dock that is supposed to do it.
Maybe i should try the patch but it seems like it defeats inheritance
completely. Well depending on probe order ...
regards,
Henning
> >> Maybe leave here with
> >> netif_info()
> >>
>
> Not good to print in rcu lock.
>
> >> And move the whole block up, we can skip the whole ACPI story if we
> >> find the MAC busy.
> >
> > That is wrong, need to know that MAC so can not move up too much.
> > But maybe above the is_valid_ether_addr
>
> The MAC passthough address is read from ACPI.
> ACPI read only happens once during r8152 driver probe.
> To keep the lock less time, do it after is_valid_ether_addr.
>
> >
> > Henning
> >
> >>> + }
> >>> + }
> >>> + rcu_read_unlock();
> >>
> >> Not sure if this function is guaranteed to only run once at a time,
> >> otherwise i think that is a race. Multiple instances could make it
> >> to this very point at the same time.
> >>
>
> Run once for one device.
> So add a safe lock.
>
> Aaron
>
> >> Henning
> >>
> >>> memcpy(sa->sa_data, buf, 6);
> >>> netif_info(tp, probe, tp->netdev,
> >>> "Using pass-thru MAC addr %pM\n",
> >>> sa->sa_data);
> >>
> >
