Messages in this thread | | | Date | Mon, 13 Jun 2022 11:37:18 +0100 | Subject | Re: [PATCH 1/3] thermal: cpufreq_cooling: Use a copy of local ops for each cooling device | From | Lukasz Luba <> |
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Hi Viresh,
Thank you for the ACKs in the other patches and suggestion in this one.
On 6/13/22 10:16, Viresh Kumar wrote: > On 10-06-22, 11:03, Lukasz Luba wrote: >> It is very unlikely that one CPU cluster would have the EM and some other >> won't have it (because EM registration failed or DT lacks needed entry). >> Although, we should avoid modifying global variable with callbacks anyway. >> Redesign this and add safety for such situation. >> >> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> >> --- >> drivers/thermal/cpufreq_cooling.c | 16 +++++++++++++--- >> 1 file changed, 13 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c >> index b8151d95a806..e33183785fac 100644 >> --- a/drivers/thermal/cpufreq_cooling.c >> +++ b/drivers/thermal/cpufreq_cooling.c >> @@ -554,7 +554,12 @@ __cpufreq_cooling_register(struct device_node *np, >> /* max_level is an index, not a counter */ >> cpufreq_cdev->max_level = i - 1; >> >> - cooling_ops = &cpufreq_cooling_ops; >> + cooling_ops = kmemdup(&cpufreq_cooling_ops, sizeof(*cooling_ops), >> + GFP_KERNEL); > > I don't like the way we are duplicating the ops here. Instead of this it would > be better to add the OPs field in the cooling device structure and fill its > fields from here. The ops structure will be allocated with the cooling device > itself. >
I think I know what you mean. Make sense. There are quite a few different cooling types of devices which are using the API thermal_of_cooling_device_register() with the custom 'ops'. We probably don't want to disturb that well working drivers and ecosystem.
Here, I've tried to align this code with the devfreq_cooling, but I might actually apply your suggestion into the devfreq cooling (so they will be still aligned). In that case both struct devfreq_cooling_device and struct cpufreq_cooling_device would get a new field: struct thermal_cooling_device_ops cooling_ops; We could then remove the 'global' variables: devfreq_cooling_ops and cpufreq_cooling_ops from where we copy. Then we would do the needed assignment to the priv 'cooling_ops' in the setup code and just use the old API thermal_of_cooling_device_register() to set the needed 'ops' pointer in the struct thermal_cooling_device.
Does this sound OK?
Regards, Lukasz
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