Il 07/12/2011 14:12, Mauro Carvalho Chehab ha scritto: > On 06-12-2011 12:33, Gianluca Gennari wrote: >> Hi All, >> >> I have a Terratec Cinergy Hybrid T USB XS stick (USB 0ccd:0042). >> This device is made of the following components: >> - Empiatech em2880 USB bridge; >> - Zarlink zl10353 demodulator; >> - Xceive XC3028 tuner; >> >> For this device, the ZARLINK456 define is set to true so it is using the >> firmwares with type D2633 for the XC3028 tuner. >> >> I found out that: >> 1) the DTV7 firmware works fine in VHF band (bw=7MHz); >> 2) the DTV8 firmware works fine in UHF band (bw=8MHz); >> 3) the DTV78 firmware works fine in UHF band (bw=8MHz) but it doesn not >> work at all in VHF band (bw=7MHz); >> >> In fact, when the DTV78 firmware is loaded and I try to tune a VHF >> channel, the frequency lock is ciclically acquired for a second and >> immediately lost. >> So the proposed patch forces a reload of the DTV7 firmware every time a >> 7MHz channel is requested. >> The only drawback is that channel change from VHF to UHF or viceversa is >> slightly slower. >> Devices using the D2620 firmwares are unaffected. > > Hi Gianluca, > > The issues with firmware DTV78 x DTV7/DTV8 are old. No matter what we do, > we end by having troubles, as the issue is Country-dependent. For example, > Australia requires a different firmware than Germany, due to the > differences > on the VHF/UHF bands. > > I prefer if you could work into a patch that would add some modprobe > parameter > to disable the current "autodetection" way, allowing to override the > firmware > used for VHF and UHF. > > Thanks, > Mauro > Hi Mauro, thanks for the feedback. Unfortunately I do not have any info on which kind of firmware is needed on other parts of the world. All I know is what is happening here in Italy, and what I can understand reading the code. I suppose my findings can be extended to the rest of Europe, and maybe Africa and Middle-East. Can you provide a reference about problems in other continents like Australia? Do you think a simple module parameters that allows to enable/disable the usage of the DTV78 firmware would do the trick? Eventually, do you agree that the default solution should be to DISABLE DTV78 firmware, since this seems to be the more robust solution, and let the user enable it through the kernel parameter if it is working in his country? Or do you prefer the other way around, so by default DTV78 firmware is enabled, and users with problems can disable it through the kernel module parameter? Best regards, Gianluca -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
