Messages in this thread |  | | Date | Fri, 14 Feb 2014 11:42:50 +0100 | From | Tomasz Figa <> | Subject | Re: [PATCH v2 4/6] ARM: firmware: add prepare_idle() operation |
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On 14.02.2014 06:16, Alexandre Courbot wrote: > On 02/13/2014 08:01 PM, Tomasz Figa wrote: >> Hi Alexandre, >> >> On 07.02.2014 05:35, Alexandre Courbot wrote: >>> Some firmwares do not put the CPU into idle mode themselves, but still >>> need to be informed that the CPU is about to enter idle mode before this >>> happens. Add a prepare_idle() operation to the firmware_ops structure to >>> handle such cases. >>> >>> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> >>> --- >>> arch/arm/include/asm/firmware.h | 4 ++++ >>> 1 file changed, 4 insertions(+) >> >> I wonder if .do_idle() couldn't simply return an appropriate error code >> to let the upper layer know that it should proceed with normal CPU idle >> activation, while still letting the firmware know that the CPU is going >> to idle. > > In our particular case I agree it would be enough to use do_idle() to > let the firmware know about the operation and have it return -ENOSYS so > the kernel actually performs it. I'm afraid this might not fulfill all > needs though (e.g. one can imagine a firmware where the OS needs to take > action between the notification and the actual shutdown), and as Stephen > pointed out that would make the name of the function ambiguous at best. > I'd rather keep it the current way for clarity. >
OK. I'm not strongly against this, just wanted some more thought on this, so please move on.
Best regards, Tomasz
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