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| author | Johan Hovold <jhovold@gmail.com> | 2013-10-22 18:32:39 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-20 12:31:40 -0800 |
| commit | be85221c4bab7fa3d930d13683b9edacc24392f3 (patch) | |
| tree | 2430d5df7e6b39df8179e824955dcd6ec4dc88e9 | |
| parent | b53ef1347bffe6f9fd40816387d2519c56c27d87 (diff) | |
| download | lwn-be85221c4bab7fa3d930d13683b9edacc24392f3.tar.gz lwn-be85221c4bab7fa3d930d13683b9edacc24392f3.zip | |
misc: atmel_pwm: add deferred-probing support
commit 5c6d6fd1564138ad048564e48639f842714a90c6 upstream.
Two drivers (atmel-pwm-bl and leds-atmel-pwm) currently depend on the
atmel_pwm driver to have bound to any pwm-device before their devices
are probed.
Support deferred probing of such devices by making sure to return
-EPROBE_DEFER from pwm_channel_alloc when no pwm-device has yet been
bound.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/misc/atmel_pwm.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/misc/atmel_pwm.c b/drivers/misc/atmel_pwm.c index 494d0500bda6..a6dc56e1bc58 100644 --- a/drivers/misc/atmel_pwm.c +++ b/drivers/misc/atmel_pwm.c @@ -90,8 +90,10 @@ int pwm_channel_alloc(int index, struct pwm_channel *ch) unsigned long flags; int status = 0; - /* insist on PWM init, with this signal pinned out */ - if (!pwm || !(pwm->mask & 1 << index)) + if (!pwm) + return -EPROBE_DEFER; + + if (!(pwm->mask & 1 << index)) return -ENODEV; if (index < 0 || index >= PWM_NCHAN || !ch) |