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| author | Johan Hovold <johan@kernel.org> | 2017-06-06 17:59:01 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-13 11:07:32 +0200 |
| commit | ed032c1bede83ec9bd5f7e803e663cb7f76e5947 (patch) | |
| tree | f09cd6eeaba0a742dab19421ddd1a2cb1a1264d0 | |
| parent | driver core: add helper to reuse a device-tree node (diff) | |
| download | linux-ed032c1bede83ec9bd5f7e803e663cb7f76e5947.tar.xz linux-ed032c1bede83ec9bd5f7e803e663cb7f76e5947.zip | |
driver core: fix automatic pinctrl management
Commit ab78029ecc34 ("drivers/pinctrl: grab default handles from device
core") added automatic pin-control management to driver core by looking
up and setting any default pinctrl state found in device tree while a
device is being probed.
This obviously runs into problems as soon as device-tree nodes are
reused for child devices which are later also probed as pins would
already have been claimed by the ancestor device.
For example if a USB host controller claims a pin, its root hub would
consequently fail to probe when its device-tree node is set to the node
of the controller:
pinctrl-single 48002030.pinmux: pin PIN204 already requested by 48064800.ehci; cannot claim for usb1
pinctrl-single 48002030.pinmux: pin-204 (usb1) status -22
pinctrl-single 48002030.pinmux: could not request pin 204 (PIN204) from group usb_dbg_pins on device pinctrl-single
usb usb1: Error applying setting, reverse things back
usb: probe of usb1 failed with error -22
Fix this by checking the new of_node_reused flag and skipping automatic
pinctrl configuration during probe if set.
Note that the flag is checked in driver core rather than in pinctrl
(e.g. in pinctrl_dt_to_map()) which would specifically have prevented
intentional use of a parent's pinctrl properties by a child device
(should such a need ever arise).
Fixes: ab78029ecc34 ("drivers/pinctrl: grab default handles from device core")
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/base/pinctrl.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/base/pinctrl.c b/drivers/base/pinctrl.c index 5917b4b5fb99..eb929dd6ef1e 100644 --- a/drivers/base/pinctrl.c +++ b/drivers/base/pinctrl.c @@ -23,6 +23,9 @@ int pinctrl_bind_pins(struct device *dev) { int ret; + if (dev->of_node_reused) + return 0; + dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL); if (!dev->pins) return -ENOMEM; |