Messages in this thread | | | Date | Mon, 18 Jun 2012 17:08:17 +0200 | From | Roland Stigge <> | Subject | Re: [PATCH] gpio: of_get_named_gpio_flags() return -EPROBE_DEFER if GPIO not yet available |
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On 06/18/2012 04:50 PM, Stephen Warren wrote: >> Can you please tell in which way the patch breaks those drivers? >> However, I can see that those drivers solved the same problem in a >> different way (deferring of_get_named_gpio(), via the sound init()). So >> they could be adjusted to take advantage of new -EPROBE_DEFER. > > The drivers I mentioned test the return code of of_get_named_gpio() to > see if it's -ENODEV, which means that DT property for that GPIO exists > but the driver for it isn't available yet, so the property can't be > parsed. In this case, the sound drivers defer their own probe. If > of_get_named_gpio() is modified to return -EPROBE_DEFER directly, then > it won't be returning -ENODEV, and hence the sound drivers' check for > -ENODEV won't fire, and hence the sound drivers will just continue their > probe assuming that the particular GPIOs are not present on the board > (since they are all optional, so anything other than an explicit > deferral error from of_get_named_gpio() is not treated as an error). > This will break sound on those platforms.
Thanks for the hint! I previously also suspected sth. like this but didn't find it in v3.5-rc3. In broonie's sound.git for-next, I now finally found it.
Should be easy to fix (replacing the if (... == -ENODEV) to -EPROBE_DEFER.
Will you provide patches as signalled, of should I? Which branch would be the correct one to build on top?
Thanks in advance,
Roland
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