MEI warnings observed in dmesg after i915 driver loaded

[hershpa]

Summary:

MEI warnings were observed in dmesg when out of tree i915 driver is loaded on RHEL 9.2 based OCP 4.13.10. Note, MEI is the original name of the driver. The out of tree driver equivalent is called CSE. Refer to dmesg output below. The goal of this issue is to understand if these warnings are expected, what is the meaning behind the warnings, and what is the root cause and potential solution.

Theory:

This behavior may be expected as we are not unloading the in-tree CSE (aka MEI) driver. As a result, the out of tree MEI driver is never loaded and thus the in-tree MEI is potentially trying to use out of tree FW to initialize. This is an incompatibility.

Solution:

Potential solution is to unload in-tree MEI and see if the out of tree MEI loads successfully and this error goes away. This solution needs to be tested. This is another potential use case for KMM to unload more than one in-tree driver.

### dmesg output:

[ 3567.884499] intel_vsec 0000:38:00.0: enabling device (0140 -> 0142)
[ 3567.885148] intel_vsec 0000:3d:00.0: enabling device (0140 -> 0142)
[ 3569.550055] [drm] I915 BACKPORTED INIT 
[ 3569.551787] i915 0000:37:00.0: [drm] GT count: 1, enabled: 1
[ 3569.551829] clipped [mem 0x000a0000-0x000bffff] to [mem 0x00100000-0x000bffff] for e820 entry [mem 0x0009f000-0x000fffff]
[ 3569.551840] clipped [mem 0x000c8000-0x000cffff] to [mem 0x00100000-0x000cffff] for e820 entry [mem 0x0009f000-0x000fffff]
[ 3569.553764] i915 0000:37:00.0: [drm] Using Transparent Hugepages
[ 3569.556825] i915 0000:37:00.0: [drm] Local memory IO size: 0x000000013cc00000
[ 3569.556827] i915 0000:37:00.0: [drm] Local memory available: 0x000000013cc00000
[ 3569.562817] i915 0000:37:00.0: [drm] GT0: GuC firmware i915/dg2_guc_70.9.1.bin version 70.9.1
[ 3569.562821] i915 0000:37:00.0: [drm] GT0: HuC firmware i915/dg2_huc_7.10.3_gsc.bin version 7.10.3
[ 3569.576980] i915 0000:37:00.0: [drm] GT0: GUC: submission enabled
[ 3569.576983] i915 0000:37:00.0: [drm] GT0: GUC: SLPC enabled
[ 3569.577276] i915 0000:37:00.0: [drm] GT0: GUC: RC enabled
[ 3569.590333] i915 0000:37:00.0: GT0: local0 bcs'0.0 clear bandwidth:74358 MB/s
[ 3569.591180] [drm] Initialized i915 1.6.0 20201103 for 0000:37:00.0 on minor 1
[ 3569.623597] i915 0000:3c:00.0: [drm] GT count: 1, enabled: 1
[ 3569.623600] mei_gsc i915.mei-gscfi.14080: FW not ready: resetting: dev_state = 2 pxp = 0
[ 3569.623617] clipped [mem 0x000a0000-0x000bffff] to [mem 0x00100000-0x000bffff] for e820 entry [mem 0x0009f000-0x000fffff]
[ 3569.623621] clipped [mem 0x000c8000-0x000cffff] to [mem 0x00100000-0x000cffff] for e820 entry [mem 0x0009f000-0x000fffff]
[ 3569.623642] mei_gsc i915.mei-gscfi.14080: unexpected reset: dev_state = ENABLED fw status = 00000345 84670000 00000000 00000000 E0020002 00000000
[ 3569.624324] mei_gsc i915.mei-gsc.14080: FW not ready: resetting: dev_state = 2 pxp = 2
[ 3569.624349] mei_gsc i915.mei-gsc.14080: unexpected reset: dev_state = ENABLED fw status = 00000345 84670000 00000000 00000000 E0020002 00000000