| Message ID | 20190108175818.705110-2-lkundrak@v3.sk (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | Add support for OLPC XO 1.75 Embedded Controller | expand |
On Tue, Jan 08, 2019 at 06:58:04PM +0100, Lubomir Rintel wrote: > 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. I would rather this is not exported to modules, it is generally unsafe to hook stuff by directly poking function pointers from module code.
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: > > 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. Lubo
diff --git a/arch/arm/kernel/reboot.c b/arch/arm/kernel/reboot.c index 3b2aa9a9fe26..71016cf19b86 100644 --- a/arch/arm/kernel/reboot.c +++ b/arch/arm/kernel/reboot.c @@ -22,6 +22,7 @@ typedef void (*phys_reset_t)(unsigned long, bool); * Function pointers to optional machine specific functions */ void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd); +EXPORT_SYMBOL_GPL(arm_pm_restart); void (*pm_power_off)(void); EXPORT_SYMBOL(pm_power_off);
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. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> --- Changes since v3: - Added the patch to the set arch/arm/kernel/reboot.c | 1 + 1 file changed, 1 insertion(+)