Am 02.04.2013 00:12, schrieb Mauro Carvalho Chehab: > Em Mon, 01 Apr 2013 22:39:28 +0200 > Frank Schäfer <fschaefer....@googlemail.com> escreveu: > >> Am 01.04.2013 21:22, schrieb Mauro Carvalho Chehab: >>> Em Mon, 01 Apr 2013 19:14:03 +0200 >>> Frank Schäfer <fschaefer....@googlemail.com> escreveu: >>> >>>> Am 18.03.2013 22:22, schrieb Mauro Carvalho Chehab: >>>>> Em Wed, 06 Mar 2013 18:44:07 +0100 >>>>> Frank Schäfer <fschaefer....@googlemail.com> escreveu: >>>>> >>>>>> Am 05.03.2013 16:43, schrieb Devin Heitmueller: >>>>>>> 2013/3/5 Mauro Carvalho Chehab <mche...@redhat.com>: >>>>>>>> The em2874 chips and upper have 2 buses. On all known devices, bus 0 is >>>>>>>> currently used only by eeprom, and bus 1 for the rest. Add support to >>>>>>>> register both buses. >>>>>>> Did you add a mutex to ensure that both buses cannot be used at the >>>>>>> same time? Because using the bus requires you to toggle a register >>>>>>> (thus you cannot be using both busses at the same time), you cannot >>>>>>> rely on the existing i2c adapter lock anymore. >>>>>>> >>>>>>> You don't want a situation where something is actively talking on bus >>>>>>> 0, and then something else tries to talk on bus 1, flips the register >>>>>>> bit and then the thread talking on bus 0 starts failing. >>>>>>> >>>>>>> Devin >>>>>> Hmm... there are several writes to EM28XX_R06_I2C_CLK in em28xx-dvb... >>>>>> See hauppauge_hvr930c_init(), terratec_h5_init() and >>>>>> terratec_htc_stick_init(). >>>>>> These functions are called from em28xx_dvb_init() at module init. >>>>>> Module init is async, so yes, this is (or could at least become) a >>>>>> problem... >>>>>> >>>>>> I wonder if we can't simply remove all those writes to >>>>>> EM28XX_R06_I2C_CLK from em28xx-dvb. >>>>>> This is what the functions are doing: >>>>>> >>>>>> hauppauge_hvr930c_init() >>>>>> ... >>>>>> em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x40); >>>>>> msleep(10); >>>>>> em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x44); >>>>>> msleep(10); >>>>>> ... [init sequence for slave at address 0x82] >>>>>> em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x44); >>>>>> msleep(30); >>>>>> em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x45); >>>>>> msleep(10); >>>>>> >>>>>> terratec_h5_init(): >>>>>> ... >>>>>> em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x40); >>>>>> msleep(10); >>>>>> em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x45); >>>>>> msleep(10); >>>>>> ... >>>>>> >>>>>> terratec_htc_stick_init() >>>>>> ... >>>>>> em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x40); >>>>>> msleep(10); >>>>>> em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x44); >>>>>> msleep(10); >>>>>> ... >>>>>> >>>>>> All three boards are using the following settings: >>>>>> .i2c_speed = EM2874_I2C_SECONDARY_BUS_SELECT | >>>>>> EM28XX_I2C_CLK_WAIT_ENABLE | EM28XX_I2C_FREQ_400_KHZ = 0x45 >>>>>> >>>>>> So what these functions are doing is >>>>>> - switch to bus A and do nothing fo 10ms >>>>>> - overwrite board settings for reg 0x06 with a local value (clears >>>>>> EM28XX_I2C_FREQ_400_KHZ permanently for the HTC-Stick !). >>>>>> >>>>>> I can test the HVR-930C next week. >>>> Ok, I finally had the chance to test with a HVR-930C, but it seems my >>>> device () is different. >> I forgot to insert the device/model of the device I tested: it's 16009, B1F0 > It has the same model as the one I have here.
Ok. > >>>> It has no slave device at i2c address 0x82, so I can't test this part. >>>> Btw, which slave device is this ? > AFAIKT, at address 0x41, there is the analog demod (avf4910b). It is not > used by Digital TV (although I'm not sure if, for this device, it needs > to be initialized or not). > > We don't have enough documentation to write a driver for avf4910b. Some > developers at the ML are trying to implement support for it for HVR-930C: > > http://www.mail-archive.com/linux-media@vger.kernel.org/msg59296.html > > There is a code pointed there for avf4910a: > > https://github.com/wurststulle/ngene_2400i/blob/2377b1fd99d91ff355a5e46881ef27ccc87cb376/avf4910a.c > > Also, maybe to access the avf4910b some different GPIO setting may be needed, > as it might be powered off by the GPIO settings initialized at device i > Yeah, I remember that. Anyway, I don't have time for this at the moment. I also think this is really Hauppauges job. These devices are still expensive (65-100€) but half working only. That's why I'm going to do it with all my Hauppauge devices: wait 5 years and then buy them used for max. 10€. Maybe I'll get back to this if it is still not working then and I find some free time, but no guarantee... ;) > >>>> Removing the temporary switches to bus A makes no difference (as expected). >>>> >>>>> There are some things there on the init sequence that can be >>>>> cleaned/removed. Those sequences generally comes from observing >>>>> what the original driver does. While it produces a working driver, >>>>> in general, it is not optimized and part of the init sequence can >>>>> be removed. >>>> Do you want me to send patches to remove these writes ? >>>> Which i2c speed settings do you suggest for the HVR-930C and the >>>> HTC-Stick (board settings: >>>> EM28XX_I2C_FREQ_400_KHZ, code overwrites it with EM28XX_I2C_FREQ_100_KHZ) ? >>> Sure. The better would be to even remove the hauppauge_hvr930c_init() >>> function, as this is just a hack, and use the setup via the em28xx-cards >>> commented entries: >>> >>> .tuner_type = TUNER_XC5000, >>> .tuner_addr = 0x41, >>> .dvb_gpio = hauppauge_930c_digital, >>> .tuner_gpio = hauppauge_930c_gpio, >> Hmm... tuner address is 0x61 for the device I tested ! >> The register sequences in em28xx-cards.c also seem to be different to >> the ones used in hauppauge_hvr930c_init() in em28xx-dvb.c... > I'm not telling that the entries there are right. They aren't. If they > where working, that data there weren't commented. This device entry > started with a clone from Terratec H5, which was the first em28xx > device with DRX-K. > > On Terratec H5, the tuner is different (based on tda8290/tda8275). > The current device initialization started as a clone of the code > under terratec_h5_init(). > > As it worked like that, the patch author that added support for HVR-930 > likely didn't touch on it. :-/ So the whole code for these devices is basically a quick and dirty hack. I also checked the init sequences in em28xx-dvb.c and the GPIO sequences and board parameters which are currently commented out... No, thank you, I'm not going to touch this under the current circumstances ! What I'm still going to do is to remove at least these writes to reg 0x06 in em28xx-dvb.c. > > The tuner for HVR930C is clearly at 0x61 address, as it can be seen at > em28xx-dvb: > > /* Attach xc5000 */ > memset(&cfg, 0, sizeof(cfg)); > cfg.i2c_address = 0x61; > cfg.if_khz = 4000; > > if (dvb->fe[0]->ops.i2c_gate_ctrl) > dvb->fe[0]->ops.i2c_gate_ctrl(dvb->fe[0], 1); > if (!dvb_attach(xc5000_attach, dvb->fe[0], > &dev->i2c_adap[dev->def_i2c_bus], > &cfg)) { > result = -EINVAL; > goto out_free; > } > >> Are you sure this will work for _all_ variants of the HVR-930C ? > Well, the current code will only work with a HVR-930C with a xc5000 tuner, > a drx-k demod and an em28xx (and an avf4910b analog TV demod). > > Any other model with a different layout, if are there any, won't work > anyway. > > While we can't discard that a different model might have a different GPIO > setting, Hauppauge tends to keep the GPIO settings equal for the same > device brand name. > > So, it seems very unlikely that any change here will keep it working for > model 16009 while breaking it for other devices. Ok, so if the changes work with my device, I can assume it works for the others (if existing and working with the current code), too. > >> I think it would be better if you would create those patches. >> I really don't like writing patches without completely understanding the >> code, not beeing able to test them and commit messages saying "Mauro >> told me to do this"... ;) >> You also didn't answer my question concerning the i2c speed settings. ;) > What question? > > Each bus may have a different max I2C speed, but the speed should not > change on the same I2C bus over the time. If the driver is doing that, > this is a bug that needs to be fixed. For the HVR-930C and the HTC stick the board setting is 400KHz which we overwrite in em28xx-dvb with 100KHz. Which means that the current code (if it is really working) uses 100KHz. So should I change the board setting to 100KHz when removing these writes to be sure we don't break anything ? I checked several datasheets of different i2c client devices, but none of them says anything concerning the supported i2c speeds... Can we assume that all devices are working with 100KHz ? And does 400KHz really make things faster ? ;) Regards, Frank > > Regards, > Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
