On Thu, Dec 11, 2014 at 11:52:10PM +0200, Laurent Pinchart wrote: > On Thursday 11 December 2014 22:47:32 Wolfram Sang wrote: > > > > Note that the I2C drives uses subsys_initcall() for historic reasons, > > > > while the DMA driver uses module_init(). This is hard to revert without > > > > introducing potential regressions on older boards. So, the I2C DMA > > > > support needs to handle deferred probe definately. I am with Laurent, I > > > > don't see any other way, but I'd be glad to be enlightened... > > > > > > While I believe that requesting the channel at transfer time is the good > > > solution, I think we should still try to move to module initcalls where > > > possible. The risk of regressions is real so proper testing is needed. My > > > question is, have you tried it ? > > > > I would need to test all boards using this driver to not fail booting. > > Usually I2C drivers are moved to subsys_initcall because they need > > access to something critical (PMIC, GPIOs...) early. I don't see a sane > > way to do that testing. > > Still, I would like to get a better view on the problems we should expect, by > testing this on the latest boards for instance. > > > Other than that, even if we move to module_init, we reduce the chance of > > getting a deferred probe, but we do not eliminate it... > > Sure, but reducing the chance of deferred probe is a good idea in my opinion > :-) Okay so what is the issue here, this statement is a bit worrying. Why do you guys want to reduce the chance of deferred probe? I assumed that issue was the channels availability... -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
