On Wed, Aug 22, 2018 at 09:34:09AM +0200, Johan Hovold wrote:

On Wed, Aug 22, 2018 at 11:02:31AM +0530, Keerthy wrote:

quoted

Enable DS0 for only those platforms on which it is functional

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
 arch/arm/mach-omap2/pm33xx-core.c    | 5 +++++
 drivers/soc/ti/pm33xx.c              | 9 +++++++++
 include/linux/platform_data/pm33xx.h | 2 ++
 3 files changed, 16 insertions(+)

diff --git a/arch/arm/mach-omap2/pm33xx-core.c b/arch/arm/mach-omap2/pm33xx-core.c
index f4971e4..f0f6e8e 100644
--- a/arch/arm/mach-omap2/pm33xx-core.c
+++ b/arch/arm/mach-omap2/pm33xx-core.c

@@ -135,6 +135,11 @@ static int am43xx_suspend(unsigned int state, int (*fn)(unsigned long),
 {
 	int ret = 0;
 
+	if (!(args & WFI_FLAG_DEEP_SLEEP0)) {
+		pr_err("DS0 mode not supported\n");
+		return -ENOTSUPP;
+	}
+
 	amx3_pre_suspend_common();
 	scu_power_mode(scu_base, SCU_PM_POWEROFF);
 	ret = cpu_suspend(args, fn);

diff --git a/drivers/soc/ti/pm33xx.c b/drivers/soc/ti/pm33xx.c
index d0dab32..53238d7 100644
--- a/drivers/soc/ti/pm33xx.c
+++ b/drivers/soc/ti/pm33xx.c

@@ -324,6 +324,15 @@ static int am33xx_pm_probe(struct platform_device *pdev)
 	suspend_wfi_flags |= WFI_FLAG_SAVE_EMIF;
 	suspend_wfi_flags |= WFI_FLAG_WAKE_M3;
 
+	/*
+	 * Deep Sleep0 mode is currently functional only on am437x-gp-evm,
+	 * am33xx-evm and boneblack family. Hence set the DS0 flag
+	 */
+	if (of_machine_is_compatible("ti,am437x-gp-evm") ||
+	    of_machine_is_compatible("ti,am335x-bone-black") ||
+	    of_machine_is_compatible("ti,am335x-evm"))
+		suspend_wfi_flags |= WFI_FLAG_DEEP_SLEEP0;

What about other (out-of-tree) machines which supports DS0 and which
this change would break?

I think this needs to be a blacklist if anything.

Please also expand in the commit message why you think this is needed.

Last, what tree is this against? There's no am43xx_suspend() in
linux-next (and you add compatibles above for am33xx too).

Sorry, there is indeed an am43xx_suspend(), but you are adding
compatibles for am33xx which use am33xx_suspend().

Johan