Messages in this thread | | | From | Ulf Hansson <> | Date | Mon, 10 Jun 2019 12:21:10 +0200 | Subject | Re: [PATCH 07/18] drivers: firmware: psci: Prepare to use OS initiated suspend mode |
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On Fri, 7 Jun 2019 at 17:17, Sudeep Holla <sudeep.holla@arm.com> wrote: > > On Mon, May 13, 2019 at 09:22:49PM +0200, Ulf Hansson wrote: > > The per CPU variable psci_power_state, contains an array of fixed values, > > which reflects the corresponding arm,psci-suspend-param parsed from DT, for > > each of the available CPU idle states. > > > > This isn't sufficient when using the hierarchical CPU topology in DT in > > combination with having PSCI OS initiated (OSI) mode enabled. More > > precisely, in OSI mode, Linux is responsible of telling the PSCI FW what > > idle state the cluster (a group of CPUs) should enter, while in PSCI > > Platform Coordinated (PC) mode, each CPU independently votes for an idle > > state of the cluster. > > > > For this reason, let's introduce an additional per CPU variable called > > domain_state and implement two helper functions to read/write its values. > > Following patches, which implements PM domain support for PSCI, will use > > the domain_state variable and set it to corresponding bits that represents > > the selected idle state for the cluster. > > > > Finally, in psci_cpu_suspend_enter() and psci_suspend_finisher(), let's > > take into account the values in the domain_state, as to get the complete > > suspend parameter. > > > > I understand it was split to ease review, but this patch also does > nothing as domain_state = 0 always. I was trying hard to find where it's > set, but I assume it will be done in later patches. Again may be this > can be squashed into the first caller of psci_set_domain_state
You have a point, but I am worried that it would look like this series is solely needed to support OSI mode. This is not the case. Let me explain.
Having $subject patch separate shows the specific changes needed to support OSI mode. The first caller of psci_set_domain_state() is added in patch9, however, patch9 is useful no matter of OSI or PC mode.
Moreover, if I squash $subject patch with patch9, I would have to squash also the subsequent patch (patch8), as it depends on $subject patch.
So, to conclude, are you happy with this as is or do you want me to squash the patches?
Kind regards Uffe
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