November 2020 - kernelnewbies@kernelnewbies.org

Re: power management
by Pankaj Vinadrao Joshi Nov. 3, 2020

Nov. 3, 2020

Hi Valdis, Actually i am trying to understand linux kernel power management stuff,what i am trying to do is simply i want my lcd light never go into sleep state, without bothering about whether my system is in freeze state or S2RAM state simply kind of resume/suspend mechanism as i am very new to linux pm i need bit info about it. i am checking following but i didnt find any clue $ grep . /sys/class/wakeup/wakeup*/device/power/wakeup /sys/class/wakeup/wakeup16/device/power/wakeup:enabled /sys/class/wakeup/wakeup17/device/power/wakeup:enabled /sys/class/wakeup/wakeup18/device/power/wakeup:enabled /sys/class/wakeup/wakeup19/device/power/wakeup:enabled /sys/class/wakeup/wakeup20/device/power/wakeup:enabled /sys/class/wakeup/wakeup21/device/power/wakeup:enabled /sys/class/wakeup/wakeup22/device/power/wakeup:enabled /sys/class/wakeup/wakeup24/device/power/wakeup:enabled /sys/class/wakeup/wakeup32/device/power/wakeup:enabled /sys/class/wakeup/wakeup7/device/power/wakeup:enabled Thanks! ________________________________ From: Valdis Kletnieks on behalf of Valdis Klētnieks Sent: Tuesday, November 3, 2020 12:28 PM To: Pankaj Vinadrao Joshi Cc: kernelnewbies(a)kernelnewbies.org Subject: Re: power management On Tue, 03 Nov 2020 06:45:29 +0000, "Pankaj Vinadrao Joshi" said: > with this my whole system is going into supend state but specifically i want my > lcd backlight or wifi in Active state without considering the state of system What use will the lcd backlight be when your graphics subsystem is powered down? And unless your wifi supports wake-on-lan, leaving it active won't do anything, because any received packets won't be processed. What problem are you trying to solve here?

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power management
by Pankaj Vinadrao Joshi Nov. 3, 2020

Nov. 3, 2020

Hi, am using ubuntu 18.04.4 and i am putting my system into S2RAM state using sysfs interface with echo mem > /sys/power/state , with this my whole system is going into supend state but specifically i want my lcd backlight or wifi in Active state without considering the state of system i mean to say to it shouldnt go into sleep state is it possible using sysfs interface? Can someone help me to achieve this? Thanks!

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sound: PCM/I2S Digital Mic & SPDIF
by Muni Sekhar Nov. 2, 2020

Nov. 2, 2020

Hello all, I’m having a Linux X86 machine and interfacing with Xilinx FPGA endpoint over PCIe. FPGA endpoint supports various audio engines like PCM/I2S ,Digital Mic & SPDIF. I’m looking for any existing linux device driver to port it for my hardware. Does the Linux kernel tree have any reference examples for these audio engines which I can use for porting it to my hardware? If so can someone please share your inputs on this. -- Thanks, Sekhar

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