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Eugen Hristev authored
During frame reception while the MCAN is in Error Passive state and the Receive Error Counter has thevalue MCAN_ECR.REC = 127, it may happen that MCAN_IR.MRAF is set although there was no Message RAM access failure. If MCAN_IR.MRAF is enabled, an interrupt to the Host CPU is generated. Work around: The Message RAM Access Failure interrupt routine needs to check whether MCAN_ECR.RP = '1' and MCAN_ECR.REC = '127'. In this case, reset MCAN_IR.MRAF. No further action is required. This affects versions older than 3.2.0 Errata explained on Sama5d2 SoC which includes this hardware block: http://ww1.microchip.com/downloads/en/DeviceDoc/SAMA5D2-Family-Silicon-Errata-and-Data-Sheet-Clarification-DS80000803B.pdf chapter 6.2 Reproducibility: If 2 devices with m_can are connected back to back, configuring different bitrate on them will lead to interrupt storm on the receiving side, with error "Message RAM access failure occurred". Another way is to have a bad hardware connection. Bad wire connection can lead to this issue as well. This patch fixes the issue according to provided workaround. Signed-off-by:
Eugen Hristev <eugen.hristev@microchip.com> Reviewed-by:
Ludovic Desroches <ludovic.desroches@microchip.com> Signed-off-by:
Marc Kleine-Budde <mkl@pengutronix.de>
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