Messages in this thread | | | Subject | Re: [PATCH 2/2] i2c: designware: Add support for a bus clock | From | Andy Shevchenko <> | Date | Tue, 17 Jul 2018 17:47:19 +0300 |
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On Tue, 2018-07-17 at 14:40 +0000, Phil Edworthy wrote: > Hi Andy, > > On 17 July 2018 15:19, Andy Shevchenko wrote: > > On Tue, 2018-07-17 at 12:42 +0000, Phil Edworthy wrote: > > > > > > While your point sounds valid (don't remember how clk_get() is > > > > implemented), NULL is also OK to have. > > > > > > Ok as in there is no bus clock, right? > > > So it should be: > > > if (!IS_ERR_OR_NULL (dev->busclk)) > > > > Nope, NULL is no error case for optional clock. > > I must be missing something here...
See how clk_prepare_enable() is implemented.
> I agree that NULL for an optional clock is not an error. However, the > code above is now: > + if (prepare) { > + /* Optional bus clock */
> + if (!IS_ERR_OR_NULL(dev->busclk)) {
Check for NULL is redundant.
> + ret = clk_prepare_enable(dev->busclk); > + if (ret) > + return ret; > + } > + > return clk_prepare_enable(dev->clk); > + } > > So, if you have a valid busclk, it gets enabled, otherwise it is > left alone.
-- Andy Shevchenko <andriy.shevchenko@linux.intel.com> Intel Finland Oy
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