Link unstable on CCR2004-1G-2XS-PCIE (DMA errors)

I’m trying to use a CCR2004-1G-2XS-PCIE in a x86 server (Supermicro X12SPL-LN4F) working as a firewall.
The Linux OS is Debian11 running the latest available kernel 5.10.0-30-amd64
The CCR2004 is also running the latest ROS 7.15.2, the configuration is near default at the moment, both the SFP28 ports are in passthu mode.
Under near gigabit loads, the interfaces seen by the OS flap frequently with some packet loss, the kernel reports DMA errors.
Searching the web for this kind of DMA errors, some people refer they are caused by the device not properly declaring their memory areas using the “RMRR” ???
The driver detected and used by Linux for the four interfaces presented to the PCI/OS by the board is:

root@linuxfw:~# modinfo atl1c
filename:       /lib/modules/5.10.0-30-amd64/kernel/drivers/net/ethernet/atheros/atl1c/atl1c.ko
license:        GPL
description:    Qualcomm Atheros 100/1000M Ethernet Network Driver
author:         Qualcomm Atheros Inc., <nic-devel@qualcomm.com>
...

Kernel errors on failures:

Jul  9 11:26:27 linuxfw kernel: [ 1013.297390] DMAR: DRHD: handling fault status reg 3
Jul  9 11:26:27 linuxfw kernel: [ 1013.297399] DMAR: [DMA Read] Request device [c3:00.0] PASID ffffffff fault addr ff4d2000 [fault reason 06] PTE Read access is not set
Jul  9 11:26:28 linuxfw kernel: [ 1013.953941] atl1c 0000:c3:00.1: atl1c: ins2 NIC Link is Down
Jul  9 11:26:30 linuxfw kernel: [ 1016.018700] atl1c 0000:c3:00.1: atl1c: ins2 NIC Link is Up<1000 Mbps Full Duplex>
Jul  9 11:27:05 linuxfw kernel: [ 1051.301787] atl1c 0000:c3:00.1: atl1c: ins2 NIC Link is Up<1000 Mbps Full Duplex>
Jul  9 11:27:06 linuxfw kernel: [ 1051.991499] atl1c 0000:c3:00.1: atl1c: ins2 NIC Link is Down
Jul  9 11:27:08 linuxfw kernel: [ 1054.009316] atl1c 0000:c3:00.1: atl1c: ins2 NIC Link is Up<1000 Mbps Full Duplex>
Jul  9 11:37:39 linuxfw kernel: [ 1685.155297] atl1c 0000:c3:00.1: atl1c: ins2 NIC Link is Up<1000 Mbps Full Duplex>
Jul  9 11:37:39 linuxfw kernel: [ 1685.305506] DMAR: DRHD: handling fault status reg 3
Jul  9 11:37:39 linuxfw kernel: [ 1685.305516] DMAR: [DMA Read] Request device [c3:00.0] PASID ffffffff fault addr fff21000 [fault reason 06] PTE Read access is not set

Here goes also the detailed lspci of the device:

root@linuxfw:~# lspci -s c3:00 -vvv
c3:00.0 Ethernet controller: Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet
	Physical Slot: 7
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR+ FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0, Cache Line Size: 32 bytes
	Interrupt: pin A routed to IRQ 214
	NUMA node: 0
	IOMMU group: 50
	Region 0: Memory at fb630000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [40] Power Management version 3
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot-,D3cold-)
		Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
		Address: 00000000fee00258  Data: 0000
	Capabilities: [70] Express (v2) Endpoint, MSI 00
		DevCap:	MaxPayload 256 bytes, PhantFunc 0, Latency L0s unlimited, L1 unlimited
			ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset- SlotPowerLimit 75.000W
		DevCtl:	CorrErr- NonFatalErr- FatalErr+ UnsupReq-
			RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
			MaxPayload 256 bytes, MaxReadReq 512 bytes
		DevSta:	CorrErr- NonFatalErr- FatalErr- UnsupReq- AuxPwr- TransPend-
		LnkCap:	Port #0, Speed 8GT/s, Width x8, ASPM not supported
			ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
		LnkCtl:	ASPM Disabled; RCB 64 bytes, Disabled- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 8GT/s (ok), Width x8 (ok)
			TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		DevCap2: Completion Timeout: Range ABCD, TimeoutDis+ NROPrPrP- LTR-
			 10BitTagComp- 10BitTagReq- OBFF Not Supported, ExtFmt- EETLPPrefix-
			 EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
			 FRS- TPHComp+ ExtTPHComp-
			 AtomicOpsCap: 32bit- 64bit- 128bitCAS-
		DevCtl2: Completion Timeout: 260ms to 900ms, TimeoutDis- LTR- OBFF Disabled,
			 AtomicOpsCtl: ReqEn-
		LnkCap2: Supported Link Speeds: 2.5-8GT/s, Crosslink- Retimer- 2Retimers- DRS-
		LnkCtl2: Target Link Speed: 8GT/s, EnterCompliance- SpeedDis-
			 Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
			 Compliance De-emphasis: -6dB
		LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete+ EqualizationPhase1+
			 EqualizationPhase2+ EqualizationPhase3+ LinkEqualizationRequest-
			 Retimer- 2Retimers- CrosslinkRes: unsupported
	Capabilities: [d0] Vital Product Data
pcilib: sysfs_read_vpd: read failed: Input/output error
		Not readable
	Capabilities: [100 v2] Advanced Error Reporting
		UESta:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq+ ACSViol-
		UEMsk:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq+ ACSViol-
		UESvrt:	DLP- SDES+ TLP+ FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
		CESta:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+
		CEMsk:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr-
		AERCap:	First Error Pointer: 00, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
			MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
		HeaderLog: 00000000 00000000 00000000 00000000
	Capabilities: [148 v1] Device Serial Number 00-00-00-00-00-00-00-00
	Capabilities: [158 v1] Secondary PCI Express
		LnkCtl3: LnkEquIntrruptEn- PerformEqu-
		LaneErrStat: 0
	Capabilities: [178 v5] Extended Capability ID 0x905
	Kernel driver in use: atl1c
	Kernel modules: atl1c

c3:00.1 Ethernet controller: Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet
	Physical Slot: 7
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR+ FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0, Cache Line Size: 32 bytes
	Interrupt: pin A routed to IRQ 215
	NUMA node: 0
	IOMMU group: 50
	Region 0: Memory at fb620000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [40] Power Management version 3
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot-,D3cold-)
		Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
		Address: 00000000fee00278  Data: 0000
	Capabilities: [70] Express (v2) Endpoint, MSI 00
		DevCap:	MaxPayload 256 bytes, PhantFunc 0, Latency L0s unlimited, L1 unlimited
			ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset- SlotPowerLimit 75.000W
		DevCtl:	CorrErr- NonFatalErr- FatalErr+ UnsupReq-
			RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
			MaxPayload 256 bytes, MaxReadReq 512 bytes
		DevSta:	CorrErr- NonFatalErr- FatalErr- UnsupReq- AuxPwr- TransPend-
		LnkCap:	Port #0, Speed 8GT/s, Width x8, ASPM not supported
			ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
		LnkCtl:	ASPM Disabled; RCB 64 bytes, Disabled- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 8GT/s (ok), Width x8 (ok)
			TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		DevCap2: Completion Timeout: Range ABCD, TimeoutDis+ NROPrPrP- LTR-
			 10BitTagComp- 10BitTagReq- OBFF Not Supported, ExtFmt- EETLPPrefix-
			 EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
			 FRS- TPHComp+ ExtTPHComp-
			 AtomicOpsCap: 32bit- 64bit- 128bitCAS-
		DevCtl2: Completion Timeout: 260ms to 900ms, TimeoutDis- LTR- OBFF Disabled,
			 AtomicOpsCtl: ReqEn-
		LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete- EqualizationPhase1-
			 EqualizationPhase2- EqualizationPhase3- LinkEqualizationRequest-
			 Retimer- 2Retimers- CrosslinkRes: unsupported
	Capabilities: [d0] Vital Product Data
pcilib: sysfs_read_vpd: read failed: Input/output error
		Not readable
	Capabilities: [100 v2] Advanced Error Reporting
		UESta:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq+ ACSViol-
		UEMsk:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq+ ACSViol-
		UESvrt:	DLP- SDES+ TLP+ FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
		CESta:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+
		CEMsk:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr-
		AERCap:	First Error Pointer: 00, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
			MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
		HeaderLog: 00000000 00000000 00000000 00000000
	Capabilities: [148 v1] Device Serial Number 00-00-00-00-00-00-00-00
	Capabilities: [178 v1] Transaction Processing Hints
		Device specific mode supported
		No steering table available
	Kernel driver in use: atl1c
	Kernel modules: atl1c

c3:00.2 Ethernet controller: Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet
	Physical Slot: 7
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR+ FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0, Cache Line Size: 32 bytes
	Interrupt: pin A routed to IRQ 18
	NUMA node: 0
	IOMMU group: 50
	Region 0: Memory at fb610000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [40] Power Management version 3
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot-,D3cold-)
		Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
		Address: 0000000000000000  Data: 0000
	Capabilities: [70] Express (v2) Endpoint, MSI 00
		DevCap:	MaxPayload 256 bytes, PhantFunc 0, Latency L0s unlimited, L1 unlimited
			ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset- SlotPowerLimit 75.000W
		DevCtl:	CorrErr- NonFatalErr- FatalErr+ UnsupReq-
			RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
			MaxPayload 256 bytes, MaxReadReq 512 bytes
		DevSta:	CorrErr- NonFatalErr- FatalErr- UnsupReq- AuxPwr- TransPend-
		LnkCap:	Port #0, Speed 8GT/s, Width x8, ASPM not supported
			ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
		LnkCtl:	ASPM Disabled; RCB 64 bytes, Disabled- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 8GT/s (ok), Width x8 (ok)
			TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		DevCap2: Completion Timeout: Range ABCD, TimeoutDis+ NROPrPrP- LTR-
			 10BitTagComp- 10BitTagReq- OBFF Not Supported, ExtFmt- EETLPPrefix-
			 EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
			 FRS- TPHComp+ ExtTPHComp-
			 AtomicOpsCap: 32bit- 64bit- 128bitCAS-
		DevCtl2: Completion Timeout: 260ms to 900ms, TimeoutDis- LTR- OBFF Disabled,
			 AtomicOpsCtl: ReqEn-
		LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete- EqualizationPhase1-
			 EqualizationPhase2- EqualizationPhase3- LinkEqualizationRequest-
			 Retimer- 2Retimers- CrosslinkRes: unsupported
	Capabilities: [d0] Vital Product Data
pcilib: sysfs_read_vpd: read failed: Input/output error
		Not readable
	Capabilities: [100 v2] Advanced Error Reporting
		UESta:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq+ ACSViol-
		UEMsk:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq+ ACSViol-
		UESvrt:	DLP- SDES+ TLP+ FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
		CESta:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+
		CEMsk:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr-
		AERCap:	First Error Pointer: 00, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
			MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
		HeaderLog: 00000000 00000000 00000000 00000000
	Capabilities: [148 v1] Device Serial Number 00-00-00-00-00-00-00-00
	Capabilities: [178 v1] Transaction Processing Hints
		Device specific mode supported
		No steering table available
	Kernel driver in use: atl1c
	Kernel modules: atl1c

c3:00.3 Ethernet controller: Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet
	Physical Slot: 7
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR+ FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0, Cache Line Size: 32 bytes
	Interrupt: pin A routed to IRQ 18
	NUMA node: 0
	IOMMU group: 50
	Region 0: Memory at fb600000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [40] Power Management version 3
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot-,D3cold-)
		Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
		Address: 0000000000000000  Data: 0000
	Capabilities: [70] Express (v2) Endpoint, MSI 00
		DevCap:	MaxPayload 256 bytes, PhantFunc 0, Latency L0s unlimited, L1 unlimited
			ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset- SlotPowerLimit 75.000W
		DevCtl:	CorrErr- NonFatalErr- FatalErr+ UnsupReq-
			RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
			MaxPayload 256 bytes, MaxReadReq 512 bytes
		DevSta:	CorrErr- NonFatalErr- FatalErr- UnsupReq- AuxPwr- TransPend-
		LnkCap:	Port #0, Speed 8GT/s, Width x8, ASPM not supported
			ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
		LnkCtl:	ASPM Disabled; RCB 64 bytes, Disabled- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 8GT/s (ok), Width x8 (ok)
			TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		DevCap2: Completion Timeout: Range ABCD, TimeoutDis+ NROPrPrP- LTR-
			 10BitTagComp- 10BitTagReq- OBFF Not Supported, ExtFmt- EETLPPrefix-
			 EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
			 FRS- TPHComp+ ExtTPHComp-
			 AtomicOpsCap: 32bit- 64bit- 128bitCAS-
		DevCtl2: Completion Timeout: 260ms to 900ms, TimeoutDis- LTR- OBFF Disabled,
			 AtomicOpsCtl: ReqEn-
		LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete- EqualizationPhase1-
			 EqualizationPhase2- EqualizationPhase3- LinkEqualizationRequest-
			 Retimer- 2Retimers- CrosslinkRes: unsupported
	Capabilities: [d0] Vital Product Data
pcilib: sysfs_read_vpd: read failed: Input/output error
		Not readable
	Capabilities: [100 v2] Advanced Error Reporting
		UESta:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq+ ACSViol-
		UEMsk:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq+ ACSViol-
		UESvrt:	DLP- SDES+ TLP+ FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
		CESta:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+
		CEMsk:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr-
		AERCap:	First Error Pointer: 00, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
			MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
		HeaderLog: 00000000 00000000 00000000 00000000
	Capabilities: [148 v1] Device Serial Number 00-00-00-00-00-00-00-00
	Capabilities: [178 v1] Transaction Processing Hints
		Device specific mode supported
		No steering table available
	Kernel driver in use: atl1c
	Kernel modules: atl1c

Hope this help to fix this problem in RouterOS or giving-me some information about specific configuration to apply to Linux.
regards.

CCR2004-1G-2XS-PCIE requires a minimum Linux kernel 5.15.25 on your Linux OS.

Thank you for the note, as the kernel have frequent updates even in Deb11, I don’t even considered the chance of being outdated for the CCR2004.
I’ll update to Debian 12 that is currently using kernel 6.1.0 as soon as possible.
regards.