Re: [PATCH 1/2] fbdev: sh-mobile: implement MIPI DSI runtime PM

[Guennadi Liakhovetski <g.liakhovetski@gmx.de>]

On Fri, 24 Dec 2010, Paul Mundt wrote:

> On Thu, Dec 23, 2010 at 01:08:34AM +0100, Guennadi Liakhovetski wrote:
> > On Thu, 23 Dec 2010, Paul Mundt wrote:
> > 
> > > On Wed, Dec 22, 2010 at 10:52:18AM +0100, Guennadi Liakhovetski wrote:
> > > > @@ -356,7 +360,9 @@ static int __init sh_mipi_probe(struct platform_device *pdev)
> > > >  		goto emap;
> > > >  	}
> > > >  
> > > > -	mipi->dsit_clk = clk_get(&pdev->dev, "dsit_clk");
> > > > +	mipi->dev = &pdev->dev;
> > > > +
> > > > +	mipi->dsit_clk = clk_get(NULL, "dsit_clk");
> > > 
> > > Why did you drop &pdev->dev from clk_get()?
> > 
> > Because that clock is not associated with that device, it sisn't work 
> > correctly until now. You also cannot associate it with that device 
> > exclusively, because it serves two devices...
> > 
> I'm not sure I see what the problem is. If there is no special lookup
> matching this clock to the device pointer then the lookup will resolve to
> whatever generically provides that clock. There is also nothing that
> stops someone from providing the same clock to multiple devices via the
> same lookup string, this is largely what clock lookups are for in the
> first place. Any move away from a device pointer to clk_get() is a step
> in the wrong direction.

That device also has other clocks, so, previously, with the device pointer 
but with an unmatching device string I was getting a wrong clock - the one 
from the device... So, it is a step in the "right" direction in the sense, 
that I am now getting a correct clock. But yes, if I can associate one 
clock with several devices, that's even better! I'll try that.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/