Messages in this thread | | | Subject | Re: Nokia N900 - audio TPA6130A2 problems | From | Ivaylo Dimitrov <> | Date | Thu, 17 Mar 2016 09:56:22 +0200 |
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Hi,
On 17.03.2016 02:49, Sebastian Reichel wrote: > > mh both, the power gpio is turned off in tpa6130a2_power(0). I guess > if you don't see the problem during probe() everything works? > > I have another idea though: In opposit to the gpio, the regulator > may also be referenced by something else/already enabled. I guess > adding a sleep after the regulator_enable() is worth a try. > > Also I wonder if the same happens, if you avoid having the module > available during boot and instead load it once everything has > settled. That would rule out any side-effects of other modules > being probed on the same i2c bus.
Well, I think I've figured it out - input pullups are not enabled on i2c bus pins, in stock kernel we have:
./devmem2 0x480021BC Value at address 0x480021BC (0x4001f1bc): 0x1180118
./devmem2 0x480021C0 Value at address 0x480021C0 (0x4001f1c0): 0x1180118
in mainline
./devmem2 0x480021BC Value at address 0x480021BC (0xb6ff01bc): 0x1000100
./devmem2 0x480021C0 Value at address 0x480021C0 (0xb6f6d1c0): 0x1000100
I wonder how i2c devices work at all :)
Will fix the board DTS file later on an will report
Regards, Ivo
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