Re: [PATCH RFT 3/3] ARM: tegra: dts: seaboard: enable keyboard

[Laxman Dewangan]

On Saturday 12 January 2013 05:09 AM, Stephen Warren wrote:
> On 01/11/2013 04:36 PM, Russell King - ARM Linux wrote:
> > On Fri, Jan 11, 2013 at 04:27:07PM -0700, Stephen Warren wrote:
> > > On 01/11/2013 04:24 PM, Russell King - ARM Linux wrote:
> > > > On Fri, Jan 11, 2013 at 04:09:59PM -0700, Stephen Warren wrote:
> > > > > On 01/11/2013 06:33 AM, Laxman Dewangan wrote:
> > > > > > 	kbc->clk = clk_get(&pdev->dev, NULL);
> > > > > > 	if (IS_ERR(kbc->clk)) {
> > > > > > 		dev_err(&pdev->dev, "failed to get keyboard clock\n");
> > > > > > 		err = PTR_ERR(kbc->clk);
> > > > > > 		goto err_iounmap;
> > > > > > 	}
> > > > > Should that check be if (!kbc-clk) instead? Or does the common clock
> > > > > framework require if (IS_ERR_OR_NULL(kbc->clk)); hopefully not since
> > > > > IS_ERR_OR_NULL shouldn't be used any more.
> > > > /**
> > > >   * clk_get - lookup and obtain a reference to a clock producer.
> > > >   * @dev: device for clock "consumer"
> > > >   * @id: clock consumer ID
> > > >   *
> > > >   * Returns a struct clk corresponding to the clock producer, or
> > > >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > >   * valid IS_ERR() condition containing errno.  ...
> > > >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > >
> > > > Or, put another way:
> > > >
> > > > 	If (!IS_ERR(clk))
> > > > 		The_Clock_Is_Valid();
> > > > 	Else
> > > > 		The_Clock_Is_Invalid();
> > > > 		The_Error = PTR_ERR(clk);
> > > OK, but that doesn't appear to be what happened in practice.
> > It's what I've been saying each time I see an abuse, the problem is
> > people don't care to read the documentation provided let alone
> > understand the interfaces.
> >
> > That's precisely why IS_ERR_OR_NULL() is to be removed.  One less
> > thing for someone to throw a dart at as a selection method to use.
> > Or maybe roll a dice.  Or whatever way they do seem to choose.
> > (Whatever that is, it's not based on any sound engineering practice
> > I can make out.)
> For the record, I did mention that IS_ERR_OR_NULL() should not be the
> solution here. And the point of my email to Laxman was that he should go
> figure out the answer to my question, which would entail reading the
> documentation/code/...

Going through clock driver, the clk_get() should return error pointer or 
valid pointer, atleast not NULL.

Probably our clock driver is returning to NULL and hence issue is 
becasue whole world, it  check for IS_ERR or !IS_ERR() and null clk 
pointer treated as !IS_ERR().

Stephen,
Which is the tree on which Prashant changes are applied. I can debug 
from that tree.


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