On Sun, Dec 26, 2021 at 1:45 PM Gabriel L. Somlo <gsomlo@xxxxxxxxx> wrote: > On Sat, Dec 25, 2021 at 06:43:22PM +0200, Andy Shevchenko wrote: > > On Wed, Dec 15, 2021 at 10:00 PM Gabriel Somlo <gsomlo@xxxxxxxxx> wrote: ... > > This is wrong. It missed the deferred probe, for example. > > > > The best approach is > > > > ret = platform_get_irq_optional(...); > > if (ret < 0 && ret != -ENXIO) > > return ret; > > if (ret > 0) > > ...we got it... > > > > It will allow the future API fix of platform_get_irq_optional() to be > > really optional. > > Thanks for the example. I still need to work in a decision to use > polling, though. How about something like this instead: > > ret = platform_get_irq_optional(...); > if (ret == -ENXIO) > goto use_polling; > if (ret < 0) > return ret; // deferred probe (-EAGAIN likely?) > if (ret > 0) > ...we got it, keep going... This doesn't define what you should do when you get 0. I suggest to take my variant with below modification if (ret > 0) ...we have IRQ... else goto USE POLLING; It will take care of the case. ... > > > +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT > > > > Why under ifdeffery? > > Because I only want to do it on 64-bit capable architectures. > > The alternative would be to call > > dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); > > on *all* architectures, but ignore the returned error (-EIO, > presumably on architetures that only support 32-bit DMA). I don't understand why you are supposed to ignore errors and why you expect to get such. > Do you think that would be cleaner? -- With Best Regards, Andy Shevchenko
