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8ef0b53831
There is possible race condition in arche platform driver for maintaining of ->state field, when shared with timesync driver. Assume device booted fine, all connected modules have been enumerated correctly. As part of suspend-resume operation we have pm_notifier callback, where we turn off SVC & APB and coldboot on resume. In the process of resume, all modules gets enumerated again, and timesync driver does come into picture everytime. So when timesync driver requests arche-platform to change the state to TIMESYNC and in the middle of sync operation, if suspend gets triggered, then execution lands into arche-platform->pm_notifier callback, leading to race condition in the driver, where it checks for (state != ACTIVE) in PM_SUSPEND_PREPARE and returns, but in PM_POST_SUSPEND it just simply coldboots SVC & APB, which would inbalance all resources (including IRQ). So we need a add check in PM_POST_SUSPEND, to make sure that, we only coldboot devices if they are in to off state, i.e. if (state != OFF) then return. Testing Done: Done regressive suspend/resume testing on EVT2 platform. Note that, I some time hit issue. Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@google.com> |
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