Messages in this thread | | | Subject | Re: [PATCH v4 2/2] can: spi: hi311x: Add Holt HI-311x CAN driver | From | Akshay Bhat <> | Date | Mon, 20 Mar 2017 15:04:46 -0400 |
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Hi Wolfgang,
On 03/20/2017 12:46 PM, Wolfgang Grandegger wrote: ..snip.. >> >> The top 3 bits of HI3110_READ_ERR (BUSOFF, TXERRP, RXERRP) are valid >> even if HI3110_INT_BUSERR is not set. > > I'm confused! If you disable BUSERR interrupts, you do not get the > status bits any longer, you said. But the manual says: "Bits 4:0 in the > ERR register can be read to determine the source of the error.", which > excludes the above bits... but obviously the controller does it that way. >
I agree this feature could use better documentation.
Based on testing:
If BUSERRIE bit in INTE is clear, On cable disconnect: No interrupts related to bus errors are generated. So status change messages do not go out.
If BUSERRIE bit in INTE is set, On cable disconnect: Interrupts are generated due to ACKERR. The interrupt routine reads the BUSOFF/TXERRP/RXERRP bits of ERR register and reports the state. If CAN_CTRLMODE_BERR_REPORTING is set, then protocol errors are also reported by the interrupt. On cable re-connect: Interrupts are generated due to TXCPLT. The interrupt routine reads the BUSOFF/TXERRP/RXERRP bits of ERR register and reports the state.
Let me know if this helps clear things up :)
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