Re: [PATCH4/4] [POWERPC] Fix cpm_uart driver

From: Scott Wood
Date: Tue Sep 25 2007 - 11:11:38 EST


On Tue, Sep 25, 2007 at 02:09:03PM +0200, Jochen Friedrich wrote:
> In cpm_uart_core.c, the operation "pinfo->rx_bd_base - DPRAM_BASE" is
> used to calculate the DPRAM offset. So DPRAM_BASE must be relative to
> dpram_vbase in commproc.c as well. However, cpm_uart_cpm1.h uses cpmp in
> commproc.c to initialize DPRAM_BASE.
>
> On ARCH=ppc, cpmp is a physical address with 1:1 virtual mapping ("well
> known address"). On ARC=powerpc, this is an address obtained by
> ioremap(), however it's a different ioremap() call than dpram_vbase is
> obtained from, so noone can guarantee
> cpmp is always the same as dpram_vbase even on ARCH=powerpc.

I have patches submitted in which they're from the same ioremap, but
I agree that using cpm_dpram_addr(0) is a more robust way.

-Scott
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