Hi Sean, > In order to open up the required power gate before any operation can be > effectively performed over the serial bus between CPU and serdev, it's > clearly essential to add common attach functions for PM domains to serdev > at the probe phase. > > Similarly, the relevant dettach function for the PM domains should be > properly and reversely added at the remove phase. > > Signed-off-by: Sean Wang <[email protected]> > Cc: Rob Herring <[email protected]> > Cc: Ulf Hansson <[email protected]> > Cc: Greg Kroah-Hartman <[email protected]> > Cc: Jiri Slaby <[email protected]> > Cc: [email protected] > --- > drivers/tty/serdev/core.c | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c > index df93b72..c93d8ee 100644 > --- a/drivers/tty/serdev/core.c > +++ b/drivers/tty/serdev/core.c > @@ -13,6 +13,7 @@ > #include <linux/module.h> > #include <linux/of.h> > #include <linux/of_device.h> > +#include <linux/pm_domain.h> > #include <linux/serdev.h> > #include <linux/slab.h> > > @@ -330,8 +331,16 @@ EXPORT_SYMBOL_GPL(serdev_device_set_tiocm); > static int serdev_drv_probe(struct device *dev) > { > const struct serdev_device_driver *sdrv = > to_serdev_device_driver(dev->driver); > + int ret; > + > + ret = dev_pm_domain_attach(dev, true); > + if (ret != -EPROBE_DEFER) { > + ret = sdrv->probe(to_serdev_device(dev)); > + if (ret) > + dev_pm_domain_detach(dev, true); > + }
so if this is deferred, when does the serdev device gets probed? > > - return sdrv->probe(to_serdev_device(dev)); > + return ret; > } > > static int serdev_drv_remove(struct device *dev) > @@ -339,6 +348,9 @@ static int serdev_drv_remove(struct device *dev) > const struct serdev_device_driver *sdrv = > to_serdev_device_driver(dev->driver); > if (sdrv->remove) > sdrv->remove(to_serdev_device(dev)); > + > + dev_pm_domain_detach(dev, true); > + > return 0; > } Regards Marcel
