Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> :
> The dm9000 takes the db->lock spin lock in dm9000_timeout() and calls
> into dm9000_init_dm9000(). For the DM9000B the PHY is reset with
> dm9000_phy_write(). That function again takes the db->lock spin lock,
> which results in a deadlock. For reference the backtrace:
[...]
> To workaround similar problem (take mutex inside spin lock ) , a
> "in_timeout" variable was added in 582379839bbd ("dm9000: avoid
> sleeping in dm9000_timeout callback"). Use this variable and not take
> the spin lock inside dm9000_phy_write() if in_timeout is true.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> ---
> During the netdev watchdog handling the dm9000 driver takes the same
> spin lock twice. Avoid this by extending an existing workaround.
> ---
I can review it but I can't really endorse it. :o)
Extending ugly workaround in pre-2000 style device drivers...
I'd rather see the thing fixed if there is some real use for it.
--
Ueimor
