To close this out, in case anyone hits it. The machine I was working on was remote and I was not able to do try the ancient solution of turning the box off and turning it off again, i.e. a proper cold boot. When I was able to try this, it worked. However I observed an interesting behaviour in the process. >From a warm boot I get this sequence in dmesg [ 21.283374] si2157 2-0060: Silicon Labs Si2157 successfully attached [ 21.283374] si2157 2-0060: Silicon Labs Si2157 successfully attached [ 21.295307] si2157 2-0062: Silicon Labs Si2157 successfully attached [ 21.295307] si2157 2-0062: Silicon Labs Si2157 successfully attached [ 22.392453] si2157 7-0060: Silicon Labs Si2157 successfully attached [ 22.392453] si2157 7-0060: Silicon Labs Si2157 successfully attached [ 22.405506] si2157 7-0062: Silicon Labs Si2157 successfully attached [ 22.405506] si2157 7-0062: Silicon Labs Si2157 successfully attached from a cold boot I get this [ 21.780082] si2157 2-0060: Silicon Labs Si2157 successfully attached [ 21.780082] si2157 2-0060: Silicon Labs Si2157 successfully attached [ 21.791839] si2157 2-0062: Silicon Labs Si2157 successfully attached [ 21.791839] si2157 2-0062: Silicon Labs Si2157 successfully attached [ 22.888459] si2157 7-0060: Silicon Labs Si2157 successfully attached [ 22.888459] si2157 7-0060: Silicon Labs Si2157 successfully attached [ 22.901286] si2157 7-0062: Silicon Labs Si2157 successfully attached [ 22.901286] si2157 7-0062: Silicon Labs Si2157 successfully attached [ 44.152638] si2157 2-0060: found a 'Silicon Labs Si2157-A30 ROM 0x50' [ 44.152638] si2157 2-0060: found a 'Silicon Labs Si2157-A30 ROM 0x50' [ 44.152672] si2157 2-0060: firmware: failed to load dvb_driver_si2157_rom50.fw (-2) [ 44.152842] si2157 2-0060: firmware: failed to load dvb_driver_si2157_rom50.fw (-2) [ 44.237515] si2157 2-0060: firmware: direct-loading firmware dvb-tuner-si2157-a30-01.fw [ 44.237662] si2157 2-0060: downloading firmware from file 'dvb-tuner-si2157-a30-01.fw' [ 44.801622] si2157 7-0060: found a 'Silicon Labs Si2157-A30 ROM 0x50' [ 44.801622] si2157 7-0060: found a 'Silicon Labs Si2157-A30 ROM 0x50' [ 44.801684] si2157 7-0060: firmware: failed to load dvb_driver_si2157_rom50.fw (-2) [ 44.801798] si2157 7-0060: firmware: failed to load dvb_driver_si2157_rom50.fw (-2) [ 44.802109] si2157 7-0060: downloading firmware from file 'dvb-tuner-si2157-a30-01.fw' [ 44.805562] si2157 7-0062: found a 'Silicon Labs Si2157-A30 ROM 0x50' [ 44.805562] si2157 7-0062: found a 'Silicon Labs Si2157-A30 ROM 0x50' [ 44.805589] si2157 7-0062: firmware: failed to load dvb_driver_si2157_rom50.fw (-2) [ 44.805697] si2157 7-0062: firmware: failed to load dvb_driver_si2157_rom50.fw (-2) [ 44.805944] si2157 7-0062: downloading firmware from file 'dvb-tuner-si2157-a30-01.fw' [ 45.514028] si2157 2-0060: firmware version: 3.0.5 [ 47.444562] si2157 7-0060: firmware version: 3.0.5 [ 47.448329] si2157 7-0062: firmware version: 3.0.5 >From this it seems that on a warm boot, we are only calling si2157_probe(), but this is insufficient for proper operation. On a cold boot, si2157_find_and_load_firmware() is also called, which generates the extra output. Not sure this can be called a bug, but certainly a 'misfeature'. In any case I don't think there's a regression wrt the 5.10 kernels, I was probably just lucky with happening to cold-boot the host.
