Hi, On Wed, Jun 27, 2012 at 8:57 PM, Peter Senna Tschudin <peter.senna@xxxxxxxxx> wrote: > > Manu, > > On Wed, Jun 27, 2012 at 9:59 AM, Manu Abraham <abraham.manu@xxxxxxxxx> wrote: > > Wonderful, instead of ignoring the return value, you ignored the whole > > function > > itself. Most of the demodulator registers are R-M-x registers. The patch > > brings > > in unwanted side-effects of R-M-x. > > Sorry for that. I'll send V2 of this patch just ignoring the return > value. Can you please send me some reference about R-M-x registers? > Unfortunately public versions of the document do not exist. But, basically the demodulator is a device that has microcontrollers, memory banks FPGA/DSP on it. Specifically, this demodulator is a bit complex device in all aspects. The registers what you see externally have different operating modes associated with it, such as Read-Only, Write-Only, Read-Modify-Write and some others where they shouldn't be accessed during certain operations and some others should be updated, such as simple read to update the interface registers, or in some cases a write of the same value to trigger some states. Even more complex are the updates which are triggered based on bit-order-significance. To summarize, the interface registers are shadowed by the on-chip microcontroller to implement a Wait Free Synchronization method. I was able to find a related description elsewhere on the Internet. http://www.patentstorm.us/patents/4342079.html Hope it helps, Regards, Manu -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
