On Fri, 2013-03-22 at 15:19 +0000, Arnd Bergmann wrote:
> On Friday 22 March 2013, Andy Shevchenko wrote:
> > There is no reason to build custom filter function and translation function
> > inside the driver in case we have no DT platform.
> >
> > This patch introduces new method dw_dma_of_controller_register() and moves
> > all
> > DT related stuff under #ifdef CONFIG_OF. It also helps to distinguish the
> > real
> > -ENODEV return code of fake one when of_dma_controller_register is not
> > implemented.
> >
> > Signed-off-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
>
> This should have no impact on the object code at all, since everything
> inside of the #ifdef is be dropped by the compiler anyway if
> of_dma_controller_register is stubbed out.
Right.
> I generally prefer to have all driver code be compiled all the time
> to catch build regressions independent of the configuration, and leave
> the #ifdefs in header files that provide the interfaces.
I don't. For checking we have special make targets:
allnoconfig - New config where all options are answered with no
allyesconfig - New config where all options are accepted with yes
allmodconfig - New config selecting modules when possible
alldefconfig - New config with all symbols set to default
> > - if (pdev->dev.of_node) {
> > - err = of_dma_controller_register(pdev->dev.of_node,
> > - dw_dma_of_xlate, dw);
> > - if (err && err != -ENODEV)
> > - dev_err(&pdev->dev,
> > - "could not register of_dma_controller\n");
> > - }
> > + if (pdev->dev.of_node)
> > + dw_dma_of_controller_register(dw);
>
> If you want to remove the "err != -ENODEV" check here, we could rewrite
> this as
>
> if (IS_ENABLED(CONFIG_OF)) && pdev->dev.of_node) {
> err = of_dma_controller_register(pdev->dev.of_node,
> dw_dma_of_xlate, dw);
> if (err)
> dev_err(&pdev->dev,
> "could not register of_dma_controller\n");
> }
>
> Or alternatively, we can change the of_dma_controller_register() stub to
> return 0 if CONFIG_OF is disabled. That would also take care of similar
> code in other dma engine drivers.
Actually to be aligned with other dmaengine code it should return
-ENOSYS. And by description ENOSYS seems suitable for "not implemented"
cases.
What about to move all CONFIG_OF stuff into separate file?
--
Andy Shevchenko <andriy.shevche...@linux.intel.com>
Intel Finland Oy
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