On Mon, Dec 05, 2005, Michael Rickmann wrote: > I have an old Typhoon DVB-S card which has the same cold boot problem as the > KNC1 which Chris Dietrich reported about in November > ( http://www.linuxtv.org/pipermail/linux-dvb/2005-November/005804.html ). ... > The explanation for my problem seems relatively straightforward. After a cold > boot as defined above the stv0299 does not respond at the > SAA7146_I2C_BUS_BIT_RATE_120 used by the current driver. > When I use SAA7146_I2C_BUS_BIT_RATE_3200 as the Metzler driver does the > frontend loads correctly but szap does not get a lock. I have also tried > SAA7146_I2C_BUS_BIT_RATE_240 and SAA7146_I2C_BUS_BIT_RATE_480. > With these the Typhoon cold boots correctly and works properly. > > It would be valuable to know wether this is a general problem of KNC1-S and > old Typhoon-S cards or wether Chris and I have some odd problems. > To find out wether my measure works replace SAA7146_I2C_BUS_BIT_RATE_120 in > ../linux/drivers/media/dvb/ttpci/budget-core.c, line 384 by e.g. > SAA7146_I2C_BUS_BIT_RATE_480 or apply attached patch. The stv0299 data sheet says that while the device is in standby mode, the I2C bus speed has to be limited to F_CLK_IN/10, which usually is 400kHz. SAA7146_I2C_BUS_BIT_RATE_120 is PCI_CLK/120 = 275kHz. So it should work. The stv0299 normally starts up in normal mode, but can be made to start up in standby by a strap pin. Can you try if it is sufficient to lower the I2C bus speed just for probing, and increase it later? e.g. in budget_av_attach(): saa7146_i2c_adapter_prepare(dev, NULL, SAA7146_I2C_BUS_BIT_RATE_480); frontend_init(budget_av); saa7146_i2c_adapter_prepare(dev, NULL, SAA7146_I2C_BUS_BIT_RATE_120); (slightly hackish, but OK for testing; if it works we should add a saa7146_i2c_set_speed() API; maybe need also handle wakeup after stv0299_sleep()) But I'm not sure if this kind of optimization is worth it, maybe I should just merge your patch. Opinions? Thanks, Johannes
