H710P controller state degraded, but pdisks and vdisks are OK

Hi, I have several PowerEdge R720 servers with PERC H710P and H710P Mini (embedded) controllers that are having issues. According to omreport, the controller is in a non-critical status and a degraded status:

Controller
ID : 1
Status : Non-Critical
Name : PERC H710P Adapter
Slot ID : PCI Slot 2
State : Degraded
Firmware Version : 21.3.0-0009
Minimum Required Firmware Version : 21.3.1-0001
Driver Version : 06.806.08.00-rh3
Minimum Required Driver Version : Not Applicable
Storport Driver Version : Not Applicable
Minimum Required Storport Driver Version : Not Applicable
Number of Connectors : 2
Rebuild Rate : 30%
BGI Rate : 30%
Check Consistency Rate : 30%
Reconstruct Rate : 30%
Alarm State : Not Applicable
Cluster Mode : Not Applicable
SCSI Initiator ID : Not Applicable
Cache Memory Size : 1024 MB
Patrol Read Mode : Auto
Patrol Read State : Stopped
Patrol Read Rate : 30%
Patrol Read Iterations : 42
Abort Check Consistency on Error : Disabled
Allow Revertible Hot Spare and Replace Member : Enabled
Load Balance : Not Applicable
Auto Replace Member on Predictive Failure : Disabled
Redundant Path view : Not Applicable
CacheCade Capable : Yes
Persistent Hot Spare : Disabled
Encryption Capable : Yes
Encryption Key Present : No
Encryption Mode : None
Preserved Cache : Not Applicable
Spin Down Unconfigured Drives : Disabled
Spin Down Hot Spares : Disabled
Spin Down Configured Drives : Disabled
Automatic Disk Power Saving (Idle C) : Disabled
Start Time (HH:MM) : Not Applicable
Time Interval for Spin Up (in Hours) : Not Applicable

Vdisk is OK:

Controller PERC H710P Adapter (Slot 2)
ID : 0
Status : Ok
Name : Virtual Disk 0
State : Ready
Hot Spare Policy violated : Not Assigned
Encrypted : No
Layout : RAID-5
Size : 3,350.25 GB (3597303545856 bytes)
T10 Protection Information Status : No
Associated Fluid Cache State : Not Applicable
Device Name : /dev/sdc
Bus Protocol : SAS
Media : HDD
Read Policy : Adaptive Read Ahead
Write Policy : Write Back
Cache Policy : Not Applicable
Stripe Element Size : 64 KB
Disk Cache Policy : Disabled

And so are the physical disks (output truncated, there are a lot of disks!):

ID : 0:2:7
Status : Ok
Name : Physical Disk 0:2:7
State : Ready
Power Status : Spun Up
Bus Protocol : SAS
Media : HDD
Part of Cache Pool : Not Applicable
Remaining Rated Write Endurance : Not Applicable
Failure Predicted : No
Revision : LS0A
Driver Version : Not Applicable
Model Number : Not Applicable
T10 PI Capable : No
Certified : Yes
Encryption Capable : No
Encrypted : Not Applicable
Progress : Not Applicable
Mirror Set ID : Not Applicable
Capacity : 558.38 GB (599550590976 bytes)
Used RAID Disk Space : 558.38 GB (599550590976 bytes)
Available RAID Disk Space : 0.00 GB (0 bytes)
Hot Spare : Dedicated
Vendor ID : DELL(tm)
Product ID : ST600MM0006
Serial No. : S0M4EMF4
Part Number : CN07YX587262251B0119A02
Negotiated Speed : 6.00 Gbps
Capable Speed : 6.00 Gbps
PCIe Negotiated Link Width : Not Applicable
PCIe Maximum Link Width : Not Applicable
Sector Size : 512B
Device Write Cache : Not Applicable
Manufacture Day : 03
Manufacture Week : 02
Manufacture Year : 2015
SAS Address : 5000C5007F103929
Form Factor : Not Available
Sub Vendor : Not Available

I had found a previous thread that suggested updating the firmware, but I cannot find a newer firmware version for the controllers (embedded or additional).

If it makes a difference, all servers are running RHEL 6.6 (Santiago)