On Wed, 1 Jul 2020 11:04:42 +0800 David Gow <davidgow@xxxxxxxxxx> wrote: > On Tue, Jun 30, 2020 at 6:07 PM Jonathan Cameron > <Jonathan.Cameron@xxxxxxxxxx> wrote: > > > > On Tue, 30 Jun 2020 00:05:52 -0700 > > David Gow <davidgow@xxxxxxxxxx> wrote: > > > > > The Analog Devices AXI ADC driver uses the devm_ioremap_resource > > > function, but does not specify a dependency on IOMEM in Kconfig. This > > > causes a build failure on architectures without IOMEM, for example, UML > > > (notably with make allyesconfig). > > > > > > Fix this by making CONFIG_ADI_AXI_ADC depend on CONFIG_IOMEM. > > > > > > Signed-off-by: David Gow <davidgow@xxxxxxxxxx> > > Hi David, > > > > Could you confirm what the build error is? I thought the stubs added in > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1bcbfbfdeb > > were meant to allow us to avoid having lots of depends on IOMEM lines for the > > few architectures who don't support it. > > No worries: > /usr/bin/ld: drivers/iio/adc/adi-axi-adc.o: in function `adi_axi_adc_probe': > torvalds-linux/drivers/iio/adc/adi-axi-adc.c:415: undefined reference > to `devm_platform_ioremap_resource' > > Alas, the devm_platform_ioremap_resource function isn't handled by the > UML stubs: it all seems to be in drivers/base/platform.c and > lib/devres.c, behind #ifdef HAS_IOMEM. > > In any case, improving IOMEM support for UML (at least for the KUnit > test case, which is my use case) is something I'd like to do. There > are only three drivers[1,2] upstream at the moment which fail to build > as-is, though, so it seemed worth trying to fix them in the meantime. > That being said, I tried just getting rid of the few #ifdef HAS_IOMEMs > around the various devm_*_ioremap functions, and everything seems to > be working... So maybe that's a false dependency given the various > stubs (at least on UML). I used this (hideously hacky) patch: > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index c0d0a5490ac6..b6f08c88e2b6 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -61,7 +61,7 @@ struct resource *platform_get_resource(struct > platform_device *dev, > } > EXPORT_SYMBOL_GPL(platform_get_resource); > > -#ifdef CONFIG_HAS_IOMEM > +#if 1//def CONFIG_HAS_IOMEM > /** > * devm_platform_get_and_ioremap_resource - call devm_ioremap_resource() for a > * platform device and get resource > diff --git a/lib/Makefile b/lib/Makefile > index b1c42c10073b..35c21af33b93 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -115,7 +115,7 @@ obj-y += math/ crypto/ > > obj-$(CONFIG_GENERIC_IOMAP) += iomap.o > obj-$(CONFIG_GENERIC_PCI_IOMAP) += pci_iomap.o > -obj-$(CONFIG_HAS_IOMEM) += iomap_copy.o devres.o > +obj-y += iomap_copy.o devres.o > obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o > obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o > > --- > > If this seems to work more broadly, I may try to clean it up and post > it for broader review. Looks like a good approach to me! Jonathan > > Cheers, > -- David
