Hi James, I have T230 and T230C (v2) and with both sticks I see invalid checksum errors. My buest guess is that they come from bad power supply decoupling on the demodulator chip. The fact that you only see errors with this commit can then be explained as a timing problem that exists because of this bad decoupling. Cheers, Jan Pieter. On 7/17/19 9:44 AM, James Hutchinson wrote:
(trying again in plain text)... I'm encountering invalid checksum errors randomly in tvheadend with my MyGica T230 DVB-T2 tuner, straight after upgrading from Debian Stretch (kernel 4.9.168) to Buster (kernel 4.19.37). For example 2019-06-29 16:32:27.259 [ INFO]:subscription: 004B: "scan" subscribing to mux "618.167MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "Freeview", service: "Raw PID Subscription" 2019-06-29 16:32:27.769 [WARNING]:tbl-eit: uk_freeview: 618.167MHz in Freeview: invalid checksum (len 1558, errors 1) 2019-06-29 16:32:27.770 [WARNING]:tbl-base: pat: 618.167MHz in Freeview: invalid checksum (len 136, errors 1) 2019-06-29 16:32:27.967 [WARNING]:tbl-base: sdt: 618.167MHz in Freeview: invalid checksum (len 971, errors 1) 2019-06-29 16:32:28.462 [WARNING]:tbl-base: pmt: 618.167MHz in Freeview: invalid checksum (len 60, errors 1) 2019-06-29 16:32:28.463 [WARNING]:tbl-base: pmt: 618.167MHz in Freeview: invalid checksum (len 46, errors 1) 2019-06-29 16:32:28.637 [WARNING]:tbl-base: pmt: 618.167MHz in Freeview: invalid checksum (len 38, errors 1) 2019-06-29 16:32:32.258 [ INFO]:mpegts: 618.167MHz in Freeview scan complete 2019-06-29 16:32:32.258 [ INFO]:subscription: 004B: "scan" unsubscribing 2019-06-29 16:32:32.259 [ INFO]:mpegts: 642MHz in Freeview - tuning on Silicon Labs Si2168 #0 : DVB-T #0 2019-06-29 16:32:32.259 [ INFO]:subscription: 004E: "scan" subscribing to mux "642MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "Freeview", service: "Raw PID Subscription" 2019-06-29 16:32:41.179 [ INFO]:mpegts: 642MHz in Freeview scan complete 2019-06-29 16:32:41.179 [ INFO]:subscription: 004E: "scan" unsubscribing 2019-06-29 16:32:41.180 [ INFO]:mpegts: 602MHz in Freeview - tuning on Silicon Labs Si2168 #0 : DVB-T #0 2019-06-29 16:32:41.180 [ INFO]:subscription: 0052: "scan" subscribing to mux "602MHz", weight: 6, adapter: "Silicon Labs Si2168 #0 : DVB-T #0", network: "Freeview", service: "Raw PID Subscription" 2019-06-29 16:32:41.835 [WARNING]:tbl-eit: uk_freeview: 602MHz in Freeview: invalid checksum (len 320, errors 1) 2019-06-29 16:32:42.109 [WARNING]:tbl-base: sdt: 602MHz in Freeview: invalid checksum (len 322, errors 1) 2019-06-29 16:32:42.314 [WARNING]:tbl-base: pmt: 602MHz in Freeview: invalid checksum (len 84, errors 1) 2019-06-29 16:32:46.180 [ INFO]:mpegts: 602MHz in Freeview scan complete 2019-06-29 16:32:46.180 [ INFO]:subscription: 0052: "scan" unsubscribing The issue is not specific to particular muxes, and happens entirely at random. If I retune then the same mux will scan without issue. It also causes data corruption when streaming with continuity counter errors in the tvh log; again retuning often resolves the problem, but i never had any such issues with kernel v4.9.x. Heres the output of lsusb to confirm my hardware id: 0572:c688 Conexant Systems (Rockwell), Inc. Geniatech T230 DVB-T2 TV Stick I've been testing various kernel versions in-between 4.9->4.19 and quickly found that the issue was introduced somewhere between 4.9->4.10. I therefore performed a (lengthy) git bisect to find out which of the 14,248 commits during the v4.10 development cycle introduced this regression. I have tracked this regression down to the following commit: 5fa8815: [media] dvb-usb-cxusb: Geniatech T230 - resync TS FIFO after lock Indeed, if I revert that commit on an upto-date kernel, I now have a stable MyGica T230 tuner once more. Please note that i've tried the latest media_build drivers and have also the 5.2 kernel; both of which have the issue, and both of which can be fixed by reverting 5fa8815. Regards, James
