Re: [PATCH v2 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver
From: Wolfgang Grandegger <hidden>
Date: 2017-03-17 07:39:36
Also in:
linux-can, linux-devicetree, lkml
Hello Akshay, Am 16.03.2017 um 23:29 schrieb Akshay Bhat:
Hi Wolfgang, On 03/16/2017 04:02 PM, Wolfgang Grandegger wrote:quoted
Looks much better now! There are message for state changes to error warning and passive. Just the following message is not correct: (000.200824) can0 20000004 [8] 00 40 00 00 00 00 5F 19 ERRORFRAME controller-problem{} error-counter-tx-rx{{95}{25}} Sorry, forgot to mention... the function can_change_state() [1] should be used for that purpose, if possible. It fixes the issue above as well.The updated driver (the one used to create the above log) is using can_change_state() function. data[1] 40 corresponds to CAN_ERR_CRTL_ACTIVE, so looks correct? Could it be that the can-utils I am using is old and not reporting state change?
Hm, yes. The raw data looks correct. You could download and build a recent version from "https://github.com/linux-can/can-utils" to check. It could also be a bug.
Tentative v4 driver for reference: http://pastebin.com/4xFVL1Sjquoted
quoted
berr-reporting off case: http://pastebin.com/fUn3j7qUDitto. I just had another look to the manual and there is this undocumented STATFE register at offset 0x1E. It's mentioned in some other parts of the doc as interrupt enable register for STATF events. I would assume the same bit layout than STATF. If you set bit 2 (BUSOFF), 3 (ERRP) and 4 (ERRW), you may get interrupts. It's worth a try, I think. If it works, it's the much better solution.The HI-311x has a INT pin and a STAT pin. The hardware I have has only the INT pin connected to the processor. If the STAT pin was also connected, then like you mentioned it could be a much better solution to use STAT for state changes.
OK, I understand.
Enabling BUSOFF/ERRP/ERRW bits in STATFE did not generate any interrupts on the INT pin. Should we make it a requirement that both INT and STAT pins need to be connected in hardware for the driver to do the error reporting?
As I said, it's the better solution, especially if interrupt flooding does harm. How does your system behave when bus errors come in due to no cable connected? So far using NAPI was mandatory. There is the problem of out-of-order message reception if handled in the isr on multi processor systems. Marc, what is the current policy? Wolfgang.