Re: [RFC 0/6] pch_can/c_can: fix races and add PCH support to c_can

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 11/26/2012 09:23 AM, Wolfgang Grandegger wrote:
> Hello,
> 
> as you might have already realized, Michael has reported problems with
> the PCH_CAN driver. With his help we try to fix these issues and add
> PCH PCI support to the C_CAN driver replacing the PCH_CAN driver sooner
> than later. Here follows my current patch stack for the records. When
> Michael's tests are successful, I'm going to post final patches.
> 
> For Michael I have prepared out-of-tree driver sources allowing to
> easily build the drivers also for older 3.x kernel versions. More
> tester are welcome.
> 
> As also pointed out by Casper, the problems are obvisouly due to races
> with stop and wakeup of the netif tx queue, managing tx_next and
> concurrent register accesses. For the moment I have fixed the races by
> adding "spin[un]lock_irqsave/restore" but, thinking more about it,
> "spinlock_bh" should be enough to protect against softirq context.
> 
> With the C_CAN driver I realized some other minor issues:
> 
> - The C/D_CAN type handling is common code and could go to
>   alloc_c_can_dev() or register_c_can_dev().
> 
> Comments are welcome.

Please make the patches based on linux-can-next/for-davem

Marc
> 
> Wolfgang.
> 
> Wolfgang Grandegger (6):
>   pch_can: add spinlock to protect tx objects
>   c_can: add spinlock to protect tx and rx objects
>   c_can: add optional reset callback
>   c_can_pci: introduce board specific PCI bar
>   c_can_pci: enable PCI bus master only for MSI
>   c_can_pci: add support for PCH CAN on Intel EG20T PCH
> 
>  drivers/net/can/c_can/c_can.c     |   24 ++++++++++++++++-
>  drivers/net/can/c_can/c_can.h     |    2 ++
>  drivers/net/can/c_can/c_can_pci.c |   54 ++++++++++++++++++++++++++++++++++---
>  drivers/net/can/pch_can.c         |   11 ++++++++
>  4 files changed, 87 insertions(+), 4 deletions(-)
> 


-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
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