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Date:   Thu, 01 Aug 2013 16:16:47 +0200
From:   John Crispin <john@phrozen.org>
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To:     Ralf Baechle <ralf@linux-mips.org>
CC:     linux-mips@linux-mips.org, Florian Fainelli <florian@openwrt.org>
Subject: Re: [PATCH] MIPS: add proper set_mode() to cevt-r4k
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> setup_irq() may fail but set_mode doesn't have a way to communicate an
> error - other than leaving back a half-wrecked system so set_mode is not
> a good place to do that kind of job.

much like the current code which does not check set_mode either. also, a 
core that boots and cannot get its clock irq is not half wrecked, its 
fully wrecked and wont be able to boot anyway.

>
> How about using get_c0_compare_int() for a solution?  Currently
> get_c0_compare_int() can not return an error.  If it could return a
> negative value to indicate the unavailability of an interrupt for
> cevt-r4k's use, that interrupt would be available for alternative use.

the code could be changed but get_c0_compare_int() returns an unsigned 
so that would require changing the return value everywhere the function 
is defined.

i still think that my proposed patch is valid, we could add a panic call 
if set_mode fails. having your kernel tell you to start an instance of 
your main clock and not being able to request said irq, does look like a 
valid cause for a panic() to me

	John