On 05/16/2013 05:14 AM, Joseph Lo wrote: > On Thu, 2013-05-16 at 07:11 +0800, Stephen Warren wrote: >> On 05/15/2013 04:27 AM, Joseph Lo wrote: >>> The Tegra114 is a quad cores SoC. Each core can be hotplugged including >>> CPU0. The hotplug sequence can be controlled by setting event trigger in >>> flow controller. Then the flow controller will take care all the power >>> sequence that include CPU up and down.
>>> tst r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN >>> + beq flow_ctrl_setting_for_lp2 >>> + >>> + /* flow controller set up for hotplug */ >>> + mov r3, #FLOW_CTRL_WAITEVENT @ For hotplug >>> + b flow_ctrl_done >>> +flow_ctrl_setting_for_lp2: >>> + /* flow controller set up for LP2 */ >>> + cmp r10, #(TEGRA30 << 8) >>> moveq r3, #FLOW_CTRL_WAIT_FOR_INTERRUPT @ For LP2 >> >> Do you need e.g. "movne r3, #0" or similar here? Otherwise, I think r3 >> ends up not being initialized. > > Yes, I will add the code when I add LP2 support for Tegra114 later. > Currently the LP2 code flow only for Tegra30, so it's OK. Ah, I see. Can we add the extra move to make sure the register is always initialized now even though the path won't be used. That way, nobody will be confused by this. >>> - movne r3, #FLOW_CTRL_WAITEVENT @ For hotplug >>> +flow_ctrl_done: >>> + cmp r10, #(TEGRA30 << 8) >>> str r3, [r2] >> >> I wonder whether creating a separate tegra114_cpu_shutdown() wouldn't be >> better, to avoid all the runtime conditional code. > > I personally think the conditional code is OK. And the ARM CPU also had > hardware for branch detection also. > > I had finished some further features for both Tegra30 and Tegra114. And > most of the code here can be shared each other at least until now I > could see. Once I see if there is a significant difference, then I would > prepare maintain the code separately too. OK, if the function gets larger with more shared, I guess it's fine. Right now, the conditional-to-non-conditional code ratio is pretty high. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
