Re: serial port 8250 messed up after coverting from little endian tobig endian on kernel 2.6.31

From: myuboot
Date: Mon Nov 02 2009 - 18:54:20 EST

The CONFIG_SWAP_IO_SPACE was set to Y, but I don't even see it using
xconfig or menuconfig. So I set it manually to n into .config file and
then did a compile - I am using buildroot. But somehow the value always
comes back to y after I type in command "make". The kernel image still
messes up the console after the console is handovered from early printk
to really ttyS01.


On Thu, 29 Oct 2009 10:26 +0200, "Shmulik Ladkani"
<jungoshmulik@xxxxxxxxx> wrote:
> On Wed, 28 Oct 2009 14:36:15 -0500 myuboot@xxxxxxxxxxx wrote:
> > I just tried UPIO_MEM32 without adding a offset of 3. But the result is
> > bad - after the kernel initializes the serial console, the console print
> > out messes up. The early printk is fine because the u-boot initialises
> > the serial port fine.
> >
> > Did I miss anything? Thanks again for your help.
> I guess you did fine with UPIO_MEM32.
> Keeping the UPIO_MEM32 approach, I suggest also to fiddle Y/N with
> CONFIG_SWAP_IO_SPACE (might be that you have it set to Y while you don't
> really need it, or vice versa).
> This is since 'readl' uses 'ioswabl' for (potential) byte-swapping of the
> read
> value. Take a look at asm/io.h and mangle-port.h.
> Most important, read your hardware documentation to determine correct
> access
> to the memory mapped serial registers.
> --
> Shmulik Ladkani Jungo Ltd.
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