Messages in this thread | | | Date | Wed, 3 Jun 2015 10:07:19 -0400 | From | Paul Gortmaker <> | Subject | Re: [PATCH 1/7] platform_device: better support builtin boilerplate avoidance |
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On 15-06-02 05:19 AM, Linus Walleij wrote: > On Thu, May 28, 2015 at 2:50 AM, Paul Gortmaker > <paul.gortmaker@windriver.com> wrote: >> [Re: [PATCH 1/7] platform_device: better support builtin boilerplate avoidance] On 12/05/2015 (Tue 13:46) Linus Walleij wrote: >> >>> This does not inhibit probe() and remove() to be >>> triggered from sysfs does it? >>> >>> What is needed on builtin drivers is to set >>> .suppress_bind_attrs = true on the struct device_driver >>> so that we inhibit the creation of sysfs files to probe >>> and remove the driver by operator intervention. >> >> Is this needed? I think we will break existing use cases if we do this. >> >> For example, I have IGB as built-in, but I can still unbind one of the >> four devices and make it available for PCI pass through to KVM with: >> >> echo "0000:0a:00.1" > /sys/bus/pci/drivers/igb/unbind >> echo "0000:0a:00.1" > /sys/bus/pci/drivers/pci-stub/bind > > Aha PCI device which noone else is dependent on, I guess > it's true. > > I think we have a problem as to what "builtin" really means.
Well, people have had trouble with what "is" means before, so I guess it is possible. However, I think here it is pretty clear that builtin means a Kconfig which is "y" and where "m" is not a possible selection.
> For example if this is a builtin regulator, clock, GPIO, DMA etc > driver, we want to suppress the binding/unbinding from userspace > too, since these drivers provide resources to others and > if you unbind them, nasty things happen. Unbinding/rebinding > is fine as long as noone else depend on you. However for > a large number of builtins, that is the case :P
So, to summarize:
1) Currently drivers can unbind that really should not do so.
2) This is not a new issue, nor is it introduced by this series.
3) We can't set policy based on built in vs modular; the only sane thing appears to be to let the driver decide itself.
Paul. --
> > Yours, > Linus Walleij >
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