> <james....@realtek.com> wrote: > > > Subject: Re: [PATCH] ARM: Add support for Realtek SOC > > > > > @@ -148,6 +148,7 @@ endif > > > > textofs-$(CONFIG_ARCH_MSM8X60) := 0x00208000 > > > > textofs-$(CONFIG_ARCH_MSM8960) := 0x00208000 > > > > textofs-$(CONFIG_ARCH_MESON) := 0x00208000 > > > > +textofs-$(CONFIG_ARCH_REALTEK) := 0x00208000 > > > > textofs-$(CONFIG_ARCH_AXXIA) := 0x00308000 > > > > > > Can you explain why this is needed for your platform? > > > > > We need to reserve memory (0x00000000 ~ 0x001B0000) for rom and boot > code. > > Ok. > > > > > +config ARCH_RTD16XX > > > > + bool "Enable support for RTD1619" > > > > + depends on ARCH_REALTEK > > > > + select ARM_GIC_V3 > > > > + select ARM_PSCI > > > > > > As I understand, this chip uses a Cortex-A55. What is the reason for > > > adding support only to the 32-bit ARM architecture rather than 64-bit? > > > > The RTD16XX platform also support the 64-bit ARM architecture. > > I will add the 64-bit ARM architecture in new version patch. > > > > > Most 64-bit SoCs are only supported with arch/arm64, but generally > > > speaking that is not a requirement. My rule of thumb is that on > > > systems with 1GB of RAM or more, one would want to run a 64-bit > > > kernel, while systems with less than that are better off with a > > > 32-bit one, but that is clearly not the only reason for picking one over > > > the > other. > > > > > Support 32-bit ARM architecture is for application compatibility. > > Generally speaking, a 64-bit kernel should work better on 64-bit hardware > even when you are running mostly 32-bit applications. However, you may have > device drivers that do not correctly set compat_ioctl handlers. > > As I said, it's no problem to allow both, just explain this in the changelog > text > for the driver, along with the need for the textofs setting. > OK.
> > > It's very unusual to see custom smp operations on an ARMv8 system, > > > as we normally use PSCI here. Can you explain what is going on here? > > > Are you able to use a boot wrapper that implements these in psci instead? > > > > > The smp operations is porting form other Realtek platform. > > > > Currently, The RTD16XX platform can use the PSCI method. > > I will add PSCI method in new version patch. > > Ok, perfect! > > > > > + timer_probe(); > > > > + tick_setup_hrtimer_broadcast(); } > > > > > > What do you need tick_setup_hrtimer_broadcast() for? I don't see any > > > other platform calling this. > > > > > I want to initialize the HR timer. > > I'm still unsure about this one. My feeling is that it should not be in the > platform code, but I don't quite understand which hardware needs it. I see > that > Lorenzo Pieralisi added the same code to arm64 in commit 9358d755bd5c > ("arm64: kernel: initialize broadcast hrtimer based clock event device"), but > nothing ever calls it on 32-bit arch/arm even though the code does get built > in > to the kernel. I will add the 'hrtimer' initialization flow in related devices drivers. > My feeling is that either you don't really need it, or this is something that > other > platforms should really do as well, and it should be called from the generic > time_init() function in arch/arm/kernel/time.c instead. > OK. I understand. > Can you try to find out more of the background here, and then move the call to > time_init() assuming it is indeed useful? I agree with you. It is not necessary to call 'time_init()' function in platform code. > Arnd > > ------Please consider the environment before printing this e-mail.