Messages in this thread | | | Date | Wed, 23 Jun 2010 04:30:47 +0100 | From | Matthew Garrett <> | Subject | Re: [PATCH v3] Add TAINT_HARDWARE_UNSUPPORTED flag |
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On Wed, Jun 23, 2010 at 12:06:38PM +0900, Paul Mundt wrote:
> What exactly is the use case supposed to be? If drivers are supposed to > call in to it for specific devices then they already have all of the > information they need for constructing a device blacklist and providing > more detailed information. If it's a configuration issue then we have > device quirks, which could also be extended to other busses as needed. In > either case, the context ought to be fairly explicit. I would much rather > see a message from the bus code stating that a specific device has been > disabled and skip the probe path entirely rather than trying to bolt on a > system-wide unsupported hardware state.
Hardware may work, it may just not work well enough that a software vendor (eg, Red Hat) wants to deal with problem reports (eg, oopses caused by a network card DMAing to the wrong place) from systems with specific bits of hardware (eg, network cards that enjoy DMAing to the wrong place occasionally). It may not even be down to technical issues - the vendor may just have chosen to refuse to support systems with old CPU families. It'd be straightforward to make the kernel simply refuse to boot on them, but it seems more elegant to let it boot and alert the user to the situation.
I don't think it's a flag that would ever be used in mainline, and Alan's suggestion to just keep a range of taint flags as vendor-specific would avoid the risk of collisions in future. But there's a minor incentive to maintain standardisation over these things in order to encourage commonality of report code.
-- Matthew Garrett | mjg59@srcf.ucam.org
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