On 06/18/2010 01:53 PM, Wolfgang Grandegger wrote: > On 06/18/2010 01:21 PM, Marc Kleine-Budde wrote: >> Wolfgang Grandegger wrote: >>> On 06/18/2010 12:44 PM, Marc Kleine-Budde wrote: >>>> Wolfgang Grandegger wrote: >>>>> On 06/18/2010 12:16 PM, Marc Kleine-Budde wrote: >>>>>> Wolfgang Grandegger wrote: >>>>>>> Hi Hans-Jürgen, >>>>>>> >>>>>>> On 06/17/2010 12:52 PM, Hans J. Koch wrote: >>>>>>>> This adds a driver for FlexCAN based CAN controllers, >>>>>>>> e.g. found in Freescale i.MX35 SoCs. >>>>>>>> >>>>>>>> The original version of this driver was posted by Sascha Hauer in July >>>>>>>> 2009: >>>>>>>> http://kerneltrap.org/mailarchive/linux-netdev/2009/7/29/6251621 >>>>>>>> >>>>>>>> I took this version, added NAPI support, and fixed some problems found >>>>>>>> during testing. Well, here is the result. Please review. >>>>>>> I briefly browsed the patch and various bits and pieces are missing or >>>>>>> not correctly implemented. Marc already pointed out a few of them: >>>>>>> >>>>>>> - I do not find can_put/get_echo_skb functions in the code. How is >>>>>>> IFF_ECHO supposed to work? >>>>>> the driver uses hardware loopback >>>>> OK, then >>>>> >>>>> dev = alloc_candev(sizeof(struct flexcan_priv), 0); >>>>> >>>>> should be used (and TX_ECHO_SKB_MAX removed) in Hans-Jürgens driver. >>>>> >>>>>>> - Support for CAN_CTRLMODE_BERR_REPORTING and do_get_berr_counter() >>>>>>> seems to be missing. >>>>>>> >>>>>>> - Make use of alloc_can_skb() and alloc_can_err_skb(). >>>>>> the last two points are already addressed in my version of the driver. >>>>> I do not see support for CAN_CTRLMODE_BERR_REPORTING in your driver >>>>> (which has nothing to do with do_get_berr_counter). >>>> oh yes...sorry, got confused. >>>> >>>> However I implemented CAN_CTRLMODE_BERR_REPORTING, i.e. turning of the >>>> bit error interrupts by default. This has the effect that no bus warning >>>> and bus passive interrupt was signalled. >>>> >>>> I should add a comment to my driver. >>> >>> I'm confused, CAN_CTRLMODE_BERR_REPORTING means that the user can enable >>> bus error reporting, which seems not be handled in the driver your sent. >>> See: >>> >>> http://lxr.linux.no/linux/drivers/net/can/sja1000/sja1000.c#L134 >>> http://lxr.linux.no/linux/drivers/net/can/sja1000/sja1000.c#L588 >> >> Which interrupts does "IRQ_BEI" include? What should >> CAN_CTRLMODE_BERR_REPORTING do? >> >> Looking at: >> http://lxr.linux.no/linux+v2.6.34/drivers/net/can/sja1000/sja1000.c#L393 >> it seems that BEI on the SJA just effects bit, form and stuff errors. > > Yes, it effects *bus errors*... actually the one you handle in > at91_poll_err_frame(). Especially the AT91_IRQ_AERR does cause the > infamous interrupt flooding (which is, btw, not treated correctly as > bus error in your driver). > >> If I disable the corresponding interrupt in the flexcan. This is >> ERR_MSK, (1 << 14 in CTRL), I don't get error warning or error passive >> interrupts either. I'm not sure about the bus off interrupt. > > Hm, my understanding is that you can disable those bus error > interrupts individually via AT91_IRQ_ERR_FRAME. > >> From my point of view this is not that what CAN_CTRLMODE_BERR_REPORTING >> should do, is it? > > It should *not* disable state change interrupts, of course. I have > started to fix some issues in the at91 driver some time ago, which > I have attached below.
Sorry, I drifted away to the at91 driver. If the flexcan hardware does not allow to disable bus error reporting individually, just do *not* support CAN_CTRLMODE_BERR_REPORTING, as you already do in your patch. Wolfgang. _______________________________________________ Socketcan-core mailing list [email protected] https://lists.berlios.de/mailman/listinfo/socketcan-core
