Hi! On Mon, May 23, 2022 at 02:51:41PM +0000, David Laight wrote: > From: Petr Malat > > Sent: 23 May 2022 15:28 > > > > One can't use memcpy on memory obtained by ioremap, because IO memory > > may have different alignment and size access restriction than the system > > memory. Use memremap as phram driver operates on RAM. > > Does that actually help? > The memcpy() is still likely to issue unaligned accesses > that the hardware can't handle. Yes, it solves the issue. Memcpy can cause unaligned access only on platforms, which can handle it. And on ARM64 it's handled only for RAM and not for a device memory (__pgprot(PROT_DEVICE_*)). Petr
