Messages in this thread | | | Date | Thu, 27 Jul 2006 18:43:07 +0100 | From | Russell King <> | Subject | Re: O_CAREFUL flag to disable open() side effects |
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On Thu, Jul 27, 2006 at 10:33:23AM -0700, H. Peter Anvin wrote: > Dumb thought: would it make sense to add an O_CAREFUL flag to open(), to > disable side effects? It seems that a number of devices have this issue > and one have to jump through weird hoops to configure them. Obviously, > a file descriptor obtained with O_CAREFUL may not be fully functional, > at the device driver's option. > > For a conventional file, directory, or block device O_CAREFUL is a > no-op.
What about door locking on block devices? That might be an undesirable side effect in some circumstances, so you might not want it to be a no-op on blockdevs.
> For ttys it would typically behave similar to O_NONBLOCK > followed immediately by a fcntl to clear the nonblock flag.
What about, eg, raising DTR and RTS ? You'd want to avoid raising those if you're not actually going to be using the port.
-- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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