RE: [PATCH v2 2/2] can: flexcan: adding platform specific details for LS1021A

[Pankaj Bansal <pankaj.bansal@nxp.com>]

> -----Original Message-----
> From: ZHU Yi (ST-FIR/ENG1-Zhu) [mailto:Yi.Zhu5@cn.bosch.com]
> Sent: Tuesday, November 21, 2017 9:01 AM
> To: Pankaj Bansal <pankaj.bansal@nxp.com>; Wolfgang Grandegger
> <wg@grandegger.com>; Marc Kleine-Budde <mkl@pengutronix.de>; linux-
> can@vger.kernel.org
> Cc: Varun Sethi <V.Sethi@nxp.com>; Poonam Aggrwal
> <poonam.aggrwal@nxp.com>; Bhupesh Sharma
> <bhupesh.sharma@freescale.com>
> Subject: RE: [PATCH v2 2/2] can: flexcan: adding platform specific details for
> LS1021A
> 
> Hello Pankaj,
> 
> >From: Pankaj Bansal [mailto:pankaj.bansal@nxp.com]
> >Sent: Tuesday, November 21, 2017 10:38 AM  [...]
> >
> >Thanks Zhu Yi. In that case do we even need to put these changes in a
> quirk?
> >Shouldn't this code be generic flexcan code, irrespective of the platform?
> If in the future version of flexcan supports the complete set of state
> interrupts, then the new core which don't need the workaround can switch it
> off easily via not specifying these quirks.
> 
> Make it irrespective of the platform will add the unnecessary overhead to the
> new core (although the overhead is little).

I understand. It's nice that you have thought of future hardware enhancements.

> 
> >
> > [...]
> >
> >I will test this after PERR_STATE quirk. But as I mentioned above, in
> >my opinion we should remove FLEXCAN_QUIRK_BROKEN_PERR_STATE, and
> make
> >these changes common for all platforms.
> Thanks, I'm looking forward to the test results. As explained above, we are
> still in the hope that FLEXCAN might improve in the future. :)
> 

Without PERR_STATE :

root@TinyDistro:~# ip link set can0 up type can bitrate 125000 restart-ms 100 berr-reporting off
[   22.507345] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
root@TinyDistro:~# ip link set can1 up type can bitrate 125000 restart-ms 100 berr-reporting off
[   30.934669] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready
root@TinyDistro:~# candump -td -e any,0:0,#FFFFFFFF &
[1] 617
root@TinyDistro:~# cangen can0 -D 11223344DEADBEEF -L 8
[   48.684839] flexcan_irq 804 reg_esr=0x00062242, reg_ecr=0x00000060, reg_ctrl=0x4a31ac55
 (000.000000)  can0  20000004   [8]  00 08 00 00 00 00 00 00   ERRORFRAME
        controller-problem{tx-error-warning}
write: No buffer space available
        **********  Short L and H signals of CAN ************
root@TinyDistro:~# [  228.338038] flexcan_irq 804 reg_esr=0x00006036, reg_ecr=0x00000000, reg_ctrl=0x4a31ac55
 (179.653204)  can0  20000040   [8]  00 00 00 00 00 00 00 00   ERRORFRAME
        bus-off
[  228.438287] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
 (000.092122)  can0  20000100   [8]  00 00 00 00 00 00 00 00   ERRORFRAME
        restarted-after-bus-off

With PERR_STATE :

root@TinyDistro:~# ip link set can0 up type can bitrate 125000 restart-ms 100 berr-reporting off
[   31.997286] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
root@TinyDistro:~# ip link set can1 up type can bitrate 125000 restart-ms 100 berr-reporting off
[   40.934824] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready
root@TinyDistro:~# candump -td -e any,0:0,#FFFFFFFF &
[1] 620
root@TinyDistro:~# cangen can0 -D 11223344DEADBEEF -L 8
[   59.314920] flexcan_irq 805 reg_esr=0x00062242, reg_ecr=0x00000060, reg_ctrl=0x4a31ac55
 (000.000000)  [   59.323862] flexcan_irq 805 reg_esr=0x00042252, reg_ecr=0x00000080, reg_ctrl=0x4a31ec55
can0  20000004   [8]  00 08 00 00 00 00 00 00   ERRORFRAME
        controller-problem{tx-error-warning}
 (000.009673)  can0  20000004   [8]  00 20 00 00 00 00 00 00   ERRORFRAME
        controller-problem{tx-error-passive}
write: No buffer space available
        **********  Short L and H signals of CAN ************
root@TinyDistro:~# [   87.995878] flexcan_irq 805 reg_esr=0x00006036, reg_ecr=0x00000000, reg_ctrl=0x4a31ac55
 (028.671291)  can0  20000040   [8]  00 00 00 00 00 00 00 00   ERRORFRAME
        bus-off
 (000.094305)  [   88.098464] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready
can0  20000100   [8]  00 00 00 00 00 00 00 00   ERRORFRAME
        restarted-after-bus-off

> Best regards
> Yi