Re: [PATCH] soc: ti: pm33xx: Enable DS0 for the platforms on which it is functional

From: J, KEERTHY
Date: Wed Aug 22 2018 - 04:20:58 EST




On 8/22/2018 1:07 PM, Johan Hovold wrote:
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:
Enable DS0 for only those platforms on which it is functional

Signed-off-by: Keerthy <j-keerthy@xxxxxx>
---
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.

Currently when one does echo mem > /sys/power/state on unsuppored machines there can be a crash or a hang. So bail out with a message.


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().

am33xx_pm_probe is a common probe function for both am33 and am43.
AFAIK for am33 family am335x-evm and am335x-bone-black support Deep Sleep mode. For am43 family am43tx-gp-evm alone supports at the moment.

Can you let me know of other am33 machines that support DS0 mode?
I could have simply used ti,am33xx compatible which covers entire am33 family but then am33xx-bone (bone white) does not support this mode.


Johan