| Message ID | 1374830110-30685-2-git-send-email-josephl@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/26/2013 03:15 AM, Joseph Lo wrote: > The common LP1 resuming procedures of LP1 on Tegra was checking the LP1 > mask first. The LP1 mask indicated that the Tegra device was in LP1 then > we need to resume the Tegra from the LP1 reset handler. > > And the LP1 was putting the SDRAM to self-refresh mode, the SDRAM wasn't > accessible when resuming from LP1. We need to copy the LP1 reset handler > to IRAM before suspending. That's why you can see the address of LP1 > reset handler was located in IRAM. That's rather hard to understand. How about: ========== Add support to the Tegra CPU reset vector to detect whether the CPU is resuming from LP1 suspend state. If it is, branch to the LP1-specific resume code. When Tegra enters the LP1 suspend state, the SDRAM controller is placed into a self-refresh state. For this reason, we must place the LP1 resume code into IRAM, so that it is accessible before SDRAM access has been re-enabled. ========== Talking about *copying* the LP1 resume code to IRAM isn't appropriate here, since nothing in this patch performs any copying of the resume code. > diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S > @@ -182,6 +182,19 @@ after_errata: > 1: > #endif > > + /* Waking up from LP1? */ > + ldr r8, [r12, #RESET_DATA(MASK_LP1)] > + tst r8, r11 @ if in_lp1 > + beq __is_not_lp1 > + cmp r10, #0 > + bne __die @ only CPU0 can be here > + ldr lr, [r12, #RESET_DATA(STARTUP_LP1)] > + THUMB( add lr, lr, #1 ) @ switch to Thumb mode > + cmp lr, #0 > + bleq __die @ no LP1 startup handler On thumb, lr==#1 at this point. I think you want to move the THUMB() instruction after the bleq. > diff --git a/arch/arm/mach-tegra/sleep.h b/arch/arm/mach-tegra/sleep.h > +#define TEGRA_IRAM_CODE_AREA (TEGRA_IRAM_BASE + SZ_4K) The layout of IRAM should be described in irammap.h not sleep.h.
diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S index 34614bd..492b10f 100644 --- a/arch/arm/mach-tegra/reset-handler.S +++ b/arch/arm/mach-tegra/reset-handler.S @@ -182,6 +182,19 @@ after_errata: 1: #endif + /* Waking up from LP1? */ + ldr r8, [r12, #RESET_DATA(MASK_LP1)] + tst r8, r11 @ if in_lp1 + beq __is_not_lp1 + cmp r10, #0 + bne __die @ only CPU0 can be here + ldr lr, [r12, #RESET_DATA(STARTUP_LP1)] + THUMB( add lr, lr, #1 ) @ switch to Thumb mode + cmp lr, #0 + bleq __die @ no LP1 startup handler + bx lr +__is_not_lp1: + /* Waking up from LP2? */ ldr r9, [r12, #RESET_DATA(MASK_LP2)] tst r9, r11 @ if in_lp2 diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c index 1ac434e..fd0bbf8 100644 --- a/arch/arm/mach-tegra/reset.c +++ b/arch/arm/mach-tegra/reset.c @@ -81,6 +81,8 @@ void __init tegra_cpu_reset_handler_init(void) #endif #ifdef CONFIG_PM_SLEEP + __tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP1] = + TEGRA_IRAM_CODE_AREA; __tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP2] = virt_to_phys((void *)tegra_resume); #endif diff --git a/arch/arm/mach-tegra/sleep.h b/arch/arm/mach-tegra/sleep.h index e907e40..e7f8b6f 100644 --- a/arch/arm/mach-tegra/sleep.h +++ b/arch/arm/mach-tegra/sleep.h @@ -29,6 +29,8 @@ + IO_APB_VIRT) #define TEGRA_PMC_VIRT (TEGRA_PMC_BASE - IO_APB_PHYS + IO_APB_VIRT) +#define TEGRA_IRAM_CODE_AREA (TEGRA_IRAM_BASE + SZ_4K) + /* PMC_SCRATCH37-39 and 41 are used for tegra_pen_lock and idle */ #define PMC_SCRATCH37 0x130 #define PMC_SCRATCH38 0x134
The common LP1 resuming procedures of LP1 on Tegra was checking the LP1 mask first. The LP1 mask indicated that the Tegra device was in LP1 then we need to resume the Tegra from the LP1 reset handler. And the LP1 was putting the SDRAM to self-refresh mode, the SDRAM wasn't accessible when resuming from LP1. We need to copy the LP1 reset handler to IRAM before suspending. That's why you can see the address of LP1 reset handler was located in IRAM. Signed-off-by: Joseph Lo <josephl@nvidia.com> --- arch/arm/mach-tegra/reset-handler.S | 13 +++++++++++++ arch/arm/mach-tegra/reset.c | 2 ++ arch/arm/mach-tegra/sleep.h | 2 ++ 3 files changed, 17 insertions(+)