Re: [V2, 2/6] tty: serial: lpuart: add little endian 32 bit register support

From: Dong Aisheng
Date: Wed May 17 2017 - 01:44:00 EST


On Wed, May 17, 2017 at 08:37:41AM +0300, Nikita Yushchenko wrote:
>
>
> 17.05.2017 06:39, Dong Aisheng wrote:
> > On Tue, May 16, 2017 at 02:15:08PM +0300, Nikita Yushchenko wrote:
> >>> static u32 lpuart32_read(void __iomem *addr)
> >>> {
> >>> - return ioread32be(addr);
> >>> + return lpuart_is_be ? ioread32be(addr) : readl(addr);
> >>> }
> >>>
> >>> static void lpuart32_write(u32 val, void __iomem *addr)
> >>> {
> >>> - iowrite32be(val, addr);
> >>> + if (lpuart_is_be)
> >>> + iowrite32be(val, addr);
> >>> + else
> >>> + writel(val, addr);
> >>> }
> >>
> >> What if this is ever executed on big endian system?
> >>
> >
> > Sorry, not catching the point...
> >
> > What issues will meet?
>
> Isn't writel() in host endian?

On big endian systems, it is supposed to run iowrite32be.

Regards
Dong Aisheng