"Nori, Sekhar" <[email protected]> writes: > On Fri, Jan 08, 2010 at 00:59:28, Kevin Hilman wrote: >> Kevin Hilman <[email protected]> writes: >> >> > Sudhakar Rajashekhara <[email protected]> writes: >> > >> >> This patch set corrects some issues with the existing EDMA >> >> driver and also adds support for EDMA resource (channel/slots) >> >> sharing between two processors (say ARM and DSP). >> >> >> >> The patch set has been tested on DM646x, OMAP-L137 and OMAP-L138 >> >> EVM boards. First 6 patches of this set are same as the previous >> >> patches. The last 3 patches are different. >> > >> > Thanks for the updated comments. >> > >> > Applying to master and queing for 2.6.34 in davinci-next. >> > >> >> After more discussions on reserving EMDA channels, I'm dropping >> patches 5 and 7-9 from the master branch and davinci-next. >> >> The DSP driver should be allocating channels it expects to >> be reserved using existing APIs. > > Kevin, > > I am still not sure if having a notion of resource reservation > in EDMA driver is such a bad idea. > > EDMA as a peripheral is built to be shared across cores and I > think the driver should expose some construct to enable resource > reservation instead of assuming that it can arbitrate resources > for all cores every time. > > Example, the DA830 is a DSP boot device and there exists a use case > where DSP boots simultaneously with the ARM. Here the DSP is not > just codecs, but has a bunch of peripheral drivers running on it. > Here, dsplink will not be able to play a role. > > Simultaneous boot-up of DSP is used to achieve fast boot-up and quick > power on response. Having DSP control peripherals helps avoid data > transfer latency.
As you proposed earlier, I'm not opposed to having EDMA reservation an option for use in board files. Feel free to update and re-send the patches where the reservation is done in board files. Kevin > PS: The use case above also requires that the kernel be instructed > not to re-initialize the EDMA common registers, but that would be > another patch. _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
