Hello Wenyou,
On Thu, Feb 12, 2015 at 10:46:49AM +0800, Wenyou Yang wrote:
> To decrease the suspend time, move copying the sram function to the sram
> initialization phase, instead of every time go to suspend.
>
> In the meanwhile, substitute fncpy() for memcpy().
>
> If there is no sram allocated for PM, the PM is not supported.
My board doesn't boot anymore with this change, I am not equipped enough
to debug more, looks like fncpy() is writing the function on top of
existing kernel code.
You said you had issues with fncpy(), I guess I am having the issue you
had.
Moving the function copy from at91_pm_sram_init() to at91_pm_suspend()
fixes the problem:
-------------------------8<-----------------------------------
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 9d74c85..31339b0 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -155,6 +155,10 @@ static void at91_pm_suspend(suspend_state_t state)
flush_cache_all();
outer_disable();
+ /* Copy the pm suspend handler to SRAM */
+ at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
+ &at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
+
at91_suspend_sram_fn(at91_pmc_base, at91_ramc_base[0],
at91_ramc_base[1], pm_data);
@@ -305,10 +309,6 @@ static void __init at91_pm_sram_init(void)
pr_warn("SRAM: Could not map\n");
return;
}
-
- /* Copy the pm suspend handler to SRAM */
- at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
- &at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
}
static void __init at91_pm_init(void)
-------------------------8<-----------------------------------
Or using memcpy() instead of fncpy() also fixes the problem:
-------------------------8<-----------------------------------
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 9d74c85..feab89a 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -307,8 +307,8 @@ static void __init at91_pm_sram_init(void)
}
/* Copy the pm suspend handler to SRAM */
- at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
- &at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
+ memcpy(at91_suspend_sram_fn, at91_pm_suspend_in_sram,
+ at91_pm_suspend_in_sram_sz);
}
static void __init at91_pm_init(void)
-------------------------8<-----------------------------------
It works and fixes the hard fault, but I have no clue why :(
Sylvain
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