On Tue, Feb 9, 2010 at 2:40 AM, Michal Simek <michal.si...@petalogix.com> wrote: > Anton Vorontsov wrote: >> >> Hi all, >> >> OF GPIO infrastructure is using dynamic GPIO bases, so it is possible >> that of_get_gpio()'s returned GPIO number will be no longer valid, or >> worse, it may point to an unexpected GPIO controller. >> >> This scenario is possible: >> >> driver A: driver B: driver C: >> --------- --------- --------- >> gpiochip_add() >> gpio = of_get_gpio() >> gpiochip_remove() >> gpiochip_add() >> gpio_request(gpio); >> gpio_set_value(gpio); >> >> That is, driver A assumes that it is working with GPIO from driver B, >> but in practice it may disappear and driver C will take its GPIO base >> number, so it will provide the same GPIO numbers. >> >> The above situation is hard to trigger, but the issue is there >> nonetheless, and so needs fixing. > > > I tested xilinx gpio driver, heartbeat trigger and access through sysfs and > I haven't found any problem. There is only small part of code for Microblaze > and it is the same with PowerPC. If is Ben OK with it, I am ok too.
I'm not convinced the changes take the best approach, so I'm not okay with it yet. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
