Hi lkp experts, On Mon, Dec 14, 2020 at 11:02:11PM +0800, Zhang Rui wrote: > On Mon, 2020-12-14 at 15:44 +0800, Chen Yu wrote: > > On Sun, Dec 13, 2020 at 11:32:50PM -0800, Srinivas Pandruvada > > wrote: > > > On Mon, 2020-12-14 at 15:33 +0800, Chen Yu wrote: > > > > On Sun, Dec 13, 2020 at 02:28:03PM -0800, Srinivas Pandruvada > > > > wrote: > > > > > > > > > > -------- Forwarded Message -------- > > > > > From: kernel test robot <lkp(a)intel.com&gt; > > > > > To: Srinivas Pandruvada < > > > > > srinivas.pandruvada(a)linux.intel.com&gt; > > > > > > > > > > "sparse warnings: (new ones prefixed by >>)" > > > > > > > drivers/thermal/intel/int340x_thermal/processor_thermal > > > > > > > _rap > > > > > > > l.c: > > > > > > > 96:5 > > > > > > > 0: sparse: sparse: cast removes address space '__iomem' > > > > > > > of > > > > > > > expression > > > > > > > > > >   > > > > >    100          rapl_mmio_priv.reg_unit = (u64)proc_priv- > > > > > > mmio_base > > > > > + > > > > > rapl_regs->reg_unit; > > > > > > > > > > > > > The reason for this warning is because proc_priv->mmio_base > > > > is of > > > > __iomem > > > > attribute that can be used by sparse to detect if there is > > > > ilegal > > > > access(only > > > > device memory region is legal). Removing this attribute would > > > > cause > > > > potential > > > > problems. A clean fix would be changing > > > > rapl_mmio_priv.reg_unit > > > > to > > > > void *__iomem > > > > and remove the (u64) cast, but that would also involve > > > > changes in > > > > struct rapl_if_priv > > > > and struct reg_action. What do you think, Rui? > > > > And if within this code we know it is a safe cast, the following > > change > > might help to prevent parse from complaining: > > -       rapl_mmio_priv.reg_unit = (u64)proc_priv->mmio_base + > > rapl_regs->reg_unit; > > +       rapl_mmio_priv.reg_unit = (u64 __force)proc_priv- > > >mmio_base + > > rapl_regs->reg_unit; > >   > we can check with LKP team tomorrow. > It looks like we could not reproduce this sparse issue locally, but it should be a valid report. May I know how we can verify in lkp that a fix works(suppose we propose a patch)?

thanks, Chenyu > thanks, > rui