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Commit d2136bce authored by Santosh Shilimkar's avatar Santosh Shilimkar Committed by Nishanth Menon
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ARM: OMAP5 / DRA7: PM: Set MPUSS-EMIF clock-domain static dependency 



With EMIF clock-domain put under hardware supervised control, memory
corruption and untraceable crashes are observed on OMAP5. Further
investigation revealed that there is a weakness in the PRCM on this
specific dynamic depedency.

The recommendation is to set MPUSS static dependency towards EMIF
clock-domain to avoid issues. This recommendation holds good for DRA7
family of devices as well.

Signed-off-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
[rnayak@ti.com: DRA7]
Signed-off-by: default avatarRajendra Nayak <rnayak@ti.com>
[nm@ti.com: conflict resolution, dra7]
Signed-off-by: default avatarNishanth Menon <nm@ti.com>
Reviewed-by: default avatarKevin Hilman <khilman@linaro.org>
Tested-by: default avatarKevin Hilman <khilman@linaro.org>
parent a89726d3

arch/arm/mach-omap2/pm44xx.c

+33 −3
Original line number Diff line number Diff line
@@ -202,6 +202,32 @@ static inline int omap4_init_static_deps(void) 
	return ret;

}



/**

 * omap5_dra7_init_static_deps - Init static clkdm dependencies on OMAP5 and

 *				 DRA7

 *

 * The dynamic dependency between MPUSS -> EMIF is broken and has

 * not worked as expected. The hardware recommendation is to

 * enable static dependencies for these to avoid system

 * lock ups or random crashes.

 */

static inline int omap5_dra7_init_static_deps(void)

{

	struct clockdomain *mpuss_clkdm, *emif_clkdm;

	int ret;



	mpuss_clkdm = clkdm_lookup("mpu_clkdm");

	emif_clkdm = clkdm_lookup("emif_clkdm");

	if (!mpuss_clkdm || !emif_clkdm)

		return -EINVAL;



	ret = clkdm_add_wkdep(mpuss_clkdm, emif_clkdm);

	if (ret)

		pr_err("Failed to add MPUSS -> EMIF wakeup dependency\n");



	return ret;

}



/**

 * omap4_pm_init_early - Does early initialization necessary for OMAP4+ devices

 *
@@ -239,9 +265,13 @@ int __init omap4_pm_init(void) 
		goto err2;

	}



	if (cpu_is_omap44xx()) {

	if (cpu_is_omap44xx())

		ret = omap4_init_static_deps();

		if (ret)

	else if (soc_is_omap54xx() || soc_is_dra7xx())

		ret = omap5_dra7_init_static_deps();



	if (ret) {

		pr_err("Failed to initialise static dependencies.\n");

		goto err2;

	}