Re: [PATCH] thermal/drivers/tsens: Add suspend to RAM support for tsens
From: Manaf Meethalavalappu Pallikunhi
Date: Sat Jan 27 2024 - 10:37:36 EST
+Maulik and Raghavendra
Hi Konrad,
On 1/25/2024 4:38 PM, Konrad Dybcio wrote:
On 1/24/24 16:25, Priyansh Jain wrote:
On 1/24/2024 6:04 PM, Konrad Dybcio wrote:
On 1/24/24 11:42, Priyansh Jain wrote:
On 1/22/2024 8:02 PM, Konrad Dybcio wrote:
On 22.01.2024 11:07, Priyansh Jain wrote:
Add suspend callback support for tsens which disables tsens
interrupts
in suspend to RAM callback.
Would it not be preferrable to have the "critical overheat", wakeup-
capable interrupts be enabled, even if the system is suspended?
As part of suspend to RAM, tsens hardware will be turned off and it
cannot generate any interrupt.Also system doesn't want to abort
suspend to RAM due to tsens interrupts since system is already
going into lowest
power state. Hence disabling tsens interrupt during suspend to RAM
callback.
Is that a hardware limitation, or a software design choice? I'm not
sure I want my phone to have thermal notifications disabled when
it's suspended.
Konrad
As part of suspend to RAM , entire SOC will be off,
What do you mean by "entire SOC[sic] will be off"? Surely the memory
controller must be on to keep refreshing the memory? Are you thinking
of suspend-to-disk (hibernation), by chance?
Yes, Memory will be in self refreshing mode(Retained). But SOC will be off
and will do cold boot to come out of S2R.
this mode (suspend to RAM) is not intended for Mobile product. Tsens
interrupts are not
disabled as part of suspend to idle(suspend mode for mobile).
That's clearly untrue, e.g. the PSCI firmware on SM8550 implements
PSCI_SYSTEM_SUSPEND, which does S2R.
IIUC, PSCI_SYSTEM_SUSPEND will be enabled only for S2R supported
products and will be removed it for others.
Maulik/Raghavendra can comment more
Konrad