I can confirm that i am getting the same results with the two patches on my setup with the Debian kernels.
Debug patch produces the same messages, and with SMB_ALERT disable patch there was no longer any interrupt triggered.

Also when booting into the previous kernel i was using (linux-image-4.19.0-17-amd64 4.19.194-3), the module loads with the default config but i am not getting any interrupt. So for my particular setup the issue only appeared after upgrading from Debian kernel 4.19 to 5.10.

Will test the second version of the patch ASAP and provide you with the results.


## Kernel 4.16

# uname -a
Linux hrbpsrv01.intra.lan 4.19.0-17-amd64 #1 SMP Debian 4.19.194-3 (2021-07-18) x86_64 GNU/Linux

# cat /proc/interrupts | grep i801
 18:          0          0          0          0          0          0          0          0   IO-APIC  18-fasteoi   i801_smbus

# dmesg
...
[ 6652.023634] i801_smbus 0000:00:1f.3: SPD Write Disable is set
[ 6652.023689] i801_smbus 0000:00:1f.3: SMBus using PCI interrupt
...


## Debian linux-image-5.10.0-9-amd64 (5.10.70-1) + Debug patch

# uname -a
Linux hrbpsrv01.intra.lan 5.10.0-9-amd64 #1 SMP Debian 5.10.70-1 (2021-09-30) x86_64 GNU/Linux

# cat /proc/interrupts | grep i801
 18:          0          0          0          0          0    7358862          0          0   IO-APIC  18-fasteoi   i801_smbus
(increase at about 100k interrupts/sec)

# dmesg
...
[  516.429120] i801_smbus 0000:00:1f.3: SPD Write Disable is set
[  516.429140] i801_smbus 0000:00:1f.3: An interrupt is pending!
[  516.429161] i801_smbus 0000:00:1f.3: SMBus using PCI interrupt
[  516.429933] i2c i2c-1: 4/4 memory slots populated (from DMI)
[  516.430337] at24 1-0050: supply vcc not found, using dummy regulator
[  516.431043] at24 1-0050: 256 byte spd EEPROM, read-only
[  516.431078] i2c i2c-1: Successfully instantiated SPD at 0x50
[  516.431455] at24 1-0051: supply vcc not found, using dummy regulator
[  516.432148] at24 1-0051: 256 byte spd EEPROM, read-only
[  516.432174] i2c i2c-1: Successfully instantiated SPD at 0x51
[  516.432576] at24 1-0052: supply vcc not found, using dummy regulator
[  516.433284] at24 1-0052: 256 byte spd EEPROM, read-only
[  516.433325] i2c i2c-1: Successfully instantiated SPD at 0x52
[  516.433748] at24 1-0053: supply vcc not found, using dummy regulator
[  516.434454] at24 1-0053: 256 byte spd EEPROM, read-only
[  516.434497] i2c i2c-1: Successfully instantiated SPD at 0x53
[  525.513104] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  525.513133] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  525.513161] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  525.513185] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  525.513209] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  525.513234] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  525.513258] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  525.513281] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  525.513316] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  525.513352] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514207] i801_isr: 297603 callbacks suppressed
[  530.514221] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514259] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514299] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514331] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514366] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514391] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514425] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514457] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514482] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  530.514507] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518261] i801_isr: 320308 callbacks suppressed
[  535.518273] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518311] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518337] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518362] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518386] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518415] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518442] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518467] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518491] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
[  535.518516] i801_smbus 0000:00:1f.3: pcicst 0x298, SMBHSTSTS 0x60
...


## Kernel 5.10 + Disable ALRM interrupt patch

# cat /proc/interrupts | grep i801
 18:          0          0          0          0          0   10567596          0          0   IO-APIC  18-fasteoi   i801_smbus
(no longer increase)

# dmesg
...
[  664.110013] i801_smbus 0000:00:1f.3: SPD Write Disable is set
[  664.110065] i801_smbus 0000:00:1f.3: SMBus using PCI interrupt
[  664.111975] i2c i2c-1: 4/4 memory slots populated (from DMI)
[  664.112460] at24 1-0050: supply vcc not found, using dummy regulator
[  664.113195] at24 1-0050: 256 byte spd EEPROM, read-only
[  664.113240] i2c i2c-1: Successfully instantiated SPD at 0x50
[  664.113657] at24 1-0051: supply vcc not found, using dummy regulator
[  664.114374] at24 1-0051: 256 byte spd EEPROM, read-only
[  664.114412] i2c i2c-1: Successfully instantiated SPD at 0x51
[  664.114823] at24 1-0052: supply vcc not found, using dummy regulator
[  664.116794] at24 1-0052: 256 byte spd EEPROM, read-only
[  664.116838] i2c i2c-1: Successfully instantiated SPD at 0x52
[  664.117288] at24 1-0053: supply vcc not found, using dummy regulator
[  664.118042] at24 1-0053: 256 byte spd EEPROM, read-only
[  664.118092] i2c i2c-1: Successfully instantiated SPD at 0x53