lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 10 Aug 2021 06:54:17 -0700 From: Prasad Sodagudi <psodagud@...eaurora.org> To: gregkh@...uxfoundation.org, rjw@...ysocki.net Cc: len.brown@...el.com, linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org, pavel@....cz, psodagud@...eaurora.org Subject: [PATCH v2] PM: sleep: core: Avoid setting power.must_resume to false This is regarding suspend/resume(s2idle) scenario of devices and difference between the LTS kernels 5.4 and 5.10 with respect to devices suspend and resume. Observing that devices suspended in suspend_late stage are not getting resumed in resume_early stage. 1) LTS kernel 5.4 kernel do not have this problem but 5.10 kernel shows this problem. 2) 'commit 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase")' is skipping the driver early_resume callbacks. In device_resume_early function dev->power.must_resume is used to skip the resume call back. It looks this function is expecting that, __device_suspend_noirq() would set dev->power.must_resume = true for the devices which does not have DPM_FLAG_MAY_SKIP_RESUME flag set. 3) Problematic scenario is as follows - During the device suspend/resume scenario all the devices in the suspend_late stage are successful and some device can fail to suspend in suspend_noirq(device_suspend_noirq-> __device_suspend_noirq) phase. As a device failed in dpm_noirq_suspend_devices phase, dpm_resume_noirq is getting called to resume devices in dpm_late_early_list in the noirq phase. 4) During the Devices_early_resume stage dpm_resume_early()-->device_resume_early() functions skipping the devices early resume callbacks. 799 if (dev_pm_skip_resume(dev)) 800 goto Skip; 5) Devices suspended in suspend_late stage are not getting resumed in Devices_early_resume stage because of 'commit 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase")' is skipping the driver early_resume callbacks when dev->power.must_resume is false. Changelog: v1 -> v2: - Fixed indentation comments. - Commit text updated to include scenario. Prasad Sodagudi (1): PM: sleep: core: Avoid setting power.must_resume to false drivers/base/power/main.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
Powered by blists - more mailing lists