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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/