Re: [PATCH v4 01/15] ARM: export arm_pm_restart()
From: Lubomir Rintel <lkundrak@v3.sk>
Date: 2019-01-09 07:24:19
Also in:
linux-devicetree, linux-pm, lkml, platform-driver-x86
On Tue, 2019-01-08 at 23:31 +0000, Russell King - ARM Linux wrote:
On Tue, Jan 08, 2019 at 06:58:04PM +0100, Lubomir Rintel wrote:quoted
The OLPC XO 1.75 laptop is rebooted with a command to the Embedded Controller. The EC driver should be a module, since most people don't need it to be compiled in.Why do you need this - is there a reason why you can't hook onto the restart_handler_list using register_restart_handler()? The registered handlers are passed the command.
Actually, yes. The restart handlers are invoked in atomic context, but the EC communication needs to block. (The 1.75 EC is actually a SPI master: a command it initiated by poking a GPIO and waiting until EC tells us it's ready to read a command.) Sorry for not mentioning that earlier, I forgot that it is the case.
I would rather this is not exported to modules, it is generally unsafe to hook stuff by directly poking function pointers from module code.
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