Re: Would devm_regulator_enable be useful ?
From: Guenter Roeck
Date: Tue Feb 04 2014 - 09:22:40 EST
On 02/04/2014 03:10 AM, Mark Brown wrote:
On Mon, Feb 03, 2014 at 02:27:26PM -0800, Guenter Roeck wrote:
On Mon, Feb 03, 2014 at 06:21:52PM +0000, Mark Brown wrote:
As previously mentioned please fix your mailer to word wrap at a
sensible limit.
I thought I did ;-). I'll try to make sure I only send e-mail to you
using mutt in the future ... but I notice that your line length is
less than the one I configured, so maybe that is the problem here.
You need to allow some room for quoting.
In both cases enabling and then leaving the resource enabled throughout
the runtime of the device isn't normally the best practice for using
them. You usually want to enable and disable at runtime with mechanisms
like runtime PM when the device is idle rather than burning power all
the time and once you start doing that managed resources don't fit so
well.
Ok, I accept that. I thought that was what devm_xxx_[disable,remove] etc
was for, though.
Sort of. They're there but that doesn't mean that they should be used
in normal operation - they should be special cases, not normal things.
Managed resources are supposed to for things that are more fire and
forget.
Isn't that a bit philosophical ? The drivers I had in mind commonly
call regulator_enable() in probe and regulator_disable() in remove.
Having device managed functions would simplify that code a lot.
If those same drivers implement pm functions, I don't see a problem
using devm_ functions in those. Sure, execution complexity is a bit
higher, but it is not as if pm functions are high volume calls.
And, after all, the existence of devm_ functions doesn't mean
that they _have_ to be used.
Guenter
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