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 no slave device at i2c address 0x82, so I can't test this part. >> Btw, which slave device is this ? >> >> 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... Are you sure this will work for _all_ variants of the HVR-930C ? 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. ;) 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
