On Fri, Jun 9, 2017 at 8:44 AM, Tobias Klauser <tklau...@distanz.ch> wrote: > On 2017-06-09 at 11:49:02 +0200, Greg Kroah-Hartman > <gre...@linuxfoundation.org> wrote: >> On Mon, Jun 05, 2017 at 02:07:34PM -0500, Alan Tull wrote: >> > From: Tobias Klauser <tklau...@distanz.ch> >> > >> > Add COMPILE_TEST to the Kconfig entry for the Altera SoCFPGA FPGA >> > Bridge. The Altera FPGA Freeze Bridge can also be used on Altera PEIe >> > FPGAs, so the driver shouldn't depend on ARCH_SOCFPGA in the first place. >> > This allows test-compiling the drivers on other architectures to catch >> > compiler errors/warnings, e.g. due to API/header changes earlier on. >> > >> > Signed-off-by: Tobias Klauser <tklau...@distanz.ch> >> > Signed-off-by: Alan Tull <at...@kernel.org> >> > --- >> > drivers/fpga/Kconfig | 4 ++-- >> > 1 file changed, 2 insertions(+), 2 deletions(-) >> >> I'll drop this patch from the series, as kbuild reports errors with it >> :( > > These are warnings from the m32r cross compiler, not errors. They are > due to the way readl() is defined on m32r (returning unsigned long > instead of u32, as all other architectures do, see [1]). On all other > architectures the patch doesn't cause any issues. There are also other > cases which are already in mainline where this issue appers, so I'd say > this patch rather uncovers the symptom of a problem rather than causing > it ;) > > [1] https://marc.info/?l=linux-kernel&m=149252925326414
Yes the issue is the way m32r defines readl(). Tobias has pointed out [2] other kernel patches cause the same warning. There is a trivial suggested workaround in [1] above (declare a local u32 to take the readl() value). Doing that would be effort to mask a known issue that lies in the m32r code though. Alan [2] https://marc.info/?l=linux-kernel&m=149260369012554&w=2
