[PATCH v2 7/7] ARM: EXYNOS: cpuidle: add secure firmware support to AFTR mode code

Bartlomiej Zolnierkiewicz
2014-06-02T13:40:21Z

On Monday, June 02, 2014 03:15:07 PM Tomasz Figa wrote:
> Hi,
>
> On 02.06.2014 14:35, Bartlomiej Zolnierkiewicz wrote:
> > * Use do_idle firmware method instead of cpu_do_idle() on boards with
> > secure firmware enabled.
> >
> > * Use sysram_ns_base_addr + 0x24 address for exynos_boot_vector_addr()
> > and sysram_ns_base_addr + 0x20 one for exynos_boot_vector_flag() on
> > boards with secure firmware enabled.
> >
> > This patch fixes hang on an attempt to enter AFTR mode for TRATS2
> > board (which uses EXYNOS4412 SoC with secure firmware enabled).
> >
> > This patch shouldn't cause any functionality changes on boards that
> > don't use secure firmware.
> >
> > Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> > Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
> > ---
> > arch/arm/mach-exynos/pm.c | 8 ++++++--
> > drivers/cpuidle/cpuidle-exynos.c | 7 ++++++-
> > 2 files changed, 12 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
> > index 0fb9a5a..62a0a5e 100644
> > --- a/arch/arm/mach-exynos/pm.c
> > +++ b/arch/arm/mach-exynos/pm.c
> > @@ -169,7 +169,9 @@ int exynos_cluster_power_state(int cluster)
> >
> > static inline void __iomem *exynos_boot_vector_addr(void)
> > {
> > - if (samsung_rev() == EXYNOS4210_REV_1_1)
> > + if (firmware_run())
> > + return sysram_ns_base_addr + 0x24;
> > + else if (samsung_rev() == EXYNOS4210_REV_1_1)
>
> Aha, so this is the use case for the function added by patch 1/7.
>
> Well, I don't see the need to do it this way and complicate the API. As
> I mentioned in my comments to patches 2/7 and 5/7, more general firmware
> operations should be taking care of setting those registers to
> appropriate values and so there shouldn't be any need to use them
> directly outside the implementation of firmware ops.

More general firmware operations would handle the secure firmware case
fine but how would you like to handle a fallback case given that you
cannot use samsung_rev() etc. in drivers/cpuidle/cpuidle-exynos.c?

> [snip]
>
> > static int idle_finisher(unsigned long flags)
> > {
> > exynos_enter_aftr();
> > - cpu_do_idle();
> > + if (firmware_run())
> > + /* no need to check the return value on EXYNOS SoCs */
> > + call_firmware_op(do_idle, FW_DO_IDLE_AFTR);
> > + else
> > + cpu_do_idle();
>
> This could be done just by
>
> if (call_firmware_op(do_idle, FW_DO_IDLE_AFTR) == -ENOSYS)
> cpu_do_idle();
>
> which is 3 lines less than with a function that is suppose to simplify
> the code.

OK.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics