Re: [PATCHv5] dmaengine: Add support for BCM2835

From: Mark Brown
Date: Sat Nov 16 2013 - 07:23:45 EST


On Sat, Nov 16, 2013 at 11:41:34AM +0000, Russell King - ARM Linux wrote:
> On Sat, Nov 16, 2013 at 11:27:54AM +0000, Mark Brown wrote:

> > We should in general be moving in that direction however it does need a
> > bit of care to make sure that there aren't any dependencies which do
> > things like discard error codes, fail to check errors or treat errors as
> > hard failures.

> I don't agree: on platforms which have done this, it's very difficult to
> tell from reading the kernel message log whether things came up correctly
> because there's soo much spew from deferred probing it's virtually
> impossible to tell whether component X initialised or whether that error
> about resource Y missing was ever resolved.

I do agree that deferred programming is far too chatty - there's a
usability issue there. This bites me a lot on some of my systems too, I
tend to read my logs with grep a lot which isn't awesome.

> If we want kernel boot logs to be useful, we really need to shut up *all*
> the drivers and subsystems whinging about being deferred probing, and only
> have the driver model core reporting this status - maybe only allow
> output about why at debug level or similar.

Yes, some sort of standardisation of how this stuff gets reported would
give us much better control of these things.

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