[U-Boot] [PATCH] eth: remove usb-ethernet devices before re-enumerating them

[Marek Vasut]

> On 01/09/2012 10:08 PM, Vincent Palatin wrote:
> > On Mon, Jan 9, 2012 at 12:57, Marek Vasut <marek.vasut at gmail.com> wrote:
> >>> Fix the crash when running several times usb_init() with a USB ethernet
> >>> device plugged.
> >>> 
> >>> Signed-off-by: Vincent Palatin <vpalatin at chromium.org>
> >>> Tested-by: Wolfgang Grandegger <wg at denx.de>
> >>> ---
> >>> 
> >>>  drivers/usb/eth/usb_ether.c |    7 +++++--
> >>>  include/net.h               |    1 +
> >>>  net/eth.c                   |   29 +++++++++++++++++++++++++++++
> >>>  3 files changed, 35 insertions(+), 2 deletions(-)
> >>> 
> >>> diff --git a/drivers/usb/eth/usb_ether.c b/drivers/usb/eth/usb_ether.c
> >>> index 6565ea5..73a0790 100644
> >>> --- a/drivers/usb/eth/usb_ether.c
> >>> +++ b/drivers/usb/eth/usb_ether.c
> >>> @@ -127,8 +127,11 @@ int usb_host_eth_scan(int mode)
> >>> 
> >>>       old_async = usb_disable_asynch(1); /* asynch transfer not allowed
> >>>       */
> >>> 
> >>> -     for (i = 0; i < USB_MAX_ETH_DEV; i++)
> >>> -             memset(&usb_eth[i], 0, sizeof(usb_eth[i]));
> >>> +     /* unregister a previously detected device */
> >>> +     for (i = 0; i < usb_max_eth_dev; i++)
> >>> +             eth_unregister(&usb_eth[i].eth_dev);
> >>> +
> >>> +     memset(usb_eth, 0, sizeof(usb_eth));
> >>> 
> >>>       for (i = 0; prob_dev[i].probe; i++) {
> >>>       
> >>>               if (prob_dev[i].before_probe)
> >>> 
> >>> diff --git a/include/net.h b/include/net.h
> >>> index e4d42c2..1707a7f 100644
> >>> --- a/include/net.h
> >>> +++ b/include/net.h
> >>> @@ -96,6 +96,7 @@ struct eth_device {
> >>> 
> >>>  extern int eth_initialize(bd_t *bis);        /* Initialize network
> >>>  subsystem
> >> 
> >> */
> >> 
> >>>  extern int eth_register(struct eth_device* dev);/* Register network
> >>>  device
> >>> 
> >>> */ +extern int eth_unregister(struct eth_device *dev);/* Remove network
> >>> device */ extern void eth_try_another(int first_restart);     /* Change
> >>> the device */ extern void eth_set_current(void);          /* set
> >>> nterface to
> >> 
> >> ethcur
> >> 
> >>> var */ extern struct eth_device *eth_get_dev(void);   /* get the
> >>> current device MAC */ diff --git a/net/eth.c b/net/eth.c
> >>> index b4b9b43..3fb5fb6 100644
> >>> --- a/net/eth.c
> >>> +++ b/net/eth.c
> >>> @@ -224,6 +224,35 @@ int eth_register(struct eth_device *dev)
> >>> 
> >>>       return 0;
> >>>  
> >>>  }
> >>> 
> >>> +int eth_unregister(struct eth_device *dev)
> >>> +{
> >>> +     struct eth_device *cur;
> >>> +
> >>> +     /* No device */
> >>> +     if (!eth_devices)
> >>> +             return -1;
> >>> +
> >>> +     for (cur = eth_devices; cur->next != eth_devices && cur->next !=
> >>> dev; +          cur = cur->next)
> >>> +             ;
> >>> +
> >>> +     /* Device not found */
> >>> +     if (cur->next != dev)
> >>> +             return -1;
> >>> +
> >>> +     cur->next = dev->next;
> >>> +
> >>> +     if (eth_devices == dev)
> >>> +             eth_devices = dev->next == eth_devices ? NULL :
> >>> dev->next; +
> >>> +     if (eth_current == dev) {
> >>> +             eth_current = eth_devices;
> >>> +             eth_current_changed();
> >>> +     }
> >>> +
> >>> +     return 0;
> >>> +}
> >>> +
> >>> 
> >>>  int eth_initialize(bd_t *bis)
> >>>  {
> >>>  
> >>>       int num_devices = 0;
> >> 
> >> Looks sane. On what hardware did this happen (just for the record)?
> > 
> > I got it on x86 and ARM (tegra2) platforms (both with an EHCI
> > controller). I did most of my testing with ASIX-based USB-ethernet
> > dongle, but the issue seems pretty generic.
> 
> It happens with *any* hardware calling eth_register() more than once
> because "struct eth_device *dev*" is memset 0 before calling
> eth_register() resulting in an endless loop when scanning the devices.

Yes, I'll try to remember to test this in the evening.

M

> 
> Viele Grüße,
> 
> Wolfgang