Dear Lucas, "De Marchi, Lucas" <lucas.demar...@intel.com> wrote on 24.06.2015 14:56:19: > On Wed, 2015-06-24 at 14:27 +0300, Mika Westerberg wrote: > > On Wed, Jun 24, 2015 at 09:36:43AM +0200, christian.rupp...@alitech.com wrot > > e: > > > Dear Lucas, > > > > > > Lucas De Marchi <lucas.de.mar...@gmail.com> wrote on 23.06.2015 19:02:03: > > > > On Tue, Jun 23, 2015 at 1:45 PM, <christian.rupp...@alitech.com> wrote: > > > > > Hello, > > > > > > > > > > Christian Ruppert/ALi_GVA/ALi wrote on 10.06.2015 17:05:16: > > > > [...] > > > > > The result is not very encouraging: Out of five (identical) > designware > > > > > > > > i2c > > > > > controllers we have on my test SOC, the first one > initialises properly > > > > > > > > but > > > > > the second one gets stuck in the famous irq loop right away when the > > > > > module is enabled in i2c_dw_init. The system never gets around to try > > > > > > > > Are you using the pci or platform driver? I noticed yesterday the pci > > > > version is failing here with a NULL pointer dereference. > > > > > > The test was performed with the platform driver (instantiated through > > > device tree). > > > I just re-checked and the ultimate problem which hangs/kills thesystem in > > > > > > my case is the IRQ loop. > > > I haven't observed any NULL pointer dereferences on the road. > > > > Thanks Christian for testing. > > > > Since the patch causes problems on your hardware, I don't think it is > > good idea to merge it. > > > Yeah, but it would be bad to ignore the problem as well. The way it is now > kills any possibility of using DW controller for reading sensors like > gyroscope, accelerometer, barometer that have higher sampling rate etc. I'll > try to come up with a new patch but since I can't reproduce the problem here > it'd be good to know if there's any means for me to test.
I'll analyse the problem a bit further and send you a description (sda and scl state at enable time) as soon as I can put my hands on an oscilloscope one evening. Greetings, Christian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
