Re: [PATCH v2 4/6] ARM: firmware: add prepare_idle() operation

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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@xxxxxxxxxx>
---
   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

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel




[Index of Archives]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [CentOS ARM]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]     [Photos]