| Message ID | e338118bb6b9f560560887eb974eb250a6c89984.1528960095.git.sean.wang@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 14 Jun 2018 at 09:14, <sean.wang@mediatek.com> wrote: > > From: Sean Wang <sean.wang@mediatek.com> > > 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 <sean.wang@mediatek.com> > Cc: Rob Herring <robh@kernel.org> > Cc: Ulf Hansson <ulf.hansson@linaro.org> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Jiri Slaby <jslaby@suse.com> > Cc: linux-serial@vger.kernel.org > --- > 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) { From 4.18 rc1 via commit 919b7308fcc4, dev_pm_domain_attach() will return better error codes. I suggest to change the above error path to: if (ret) return ret; Then continue with the probing below. > + ret = sdrv->probe(to_serdev_device(dev)); > + if (ret) > + dev_pm_domain_detach(dev, true); > + } > > - 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; > } > > -- > 2.7.4 > Otherwise, this makes sense to me! Kind regards Uffe
On Thu, 2018-06-14 at 10:58 +0200, Ulf Hansson wrote: > On Thu, 14 Jun 2018 at 09:14, <sean.wang@mediatek.com> wrote: > > > > From: Sean Wang <sean.wang@mediatek.com> > > > > 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 <sean.wang@mediatek.com> > > Cc: Rob Herring <robh@kernel.org> > > Cc: Ulf Hansson <ulf.hansson@linaro.org> > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > Cc: Jiri Slaby <jslaby@suse.com> > > Cc: linux-serial@vger.kernel.org > > --- > > 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) { > > From 4.18 rc1 via commit 919b7308fcc4, dev_pm_domain_attach() will > return better error codes. > > I suggest to change the above error path to: > if (ret) > return ret; > > Then continue with the probing below. Thanks for sharing me the information. I'll happily respin using the patch because it makes the most sense. > > > + ret = sdrv->probe(to_serdev_device(dev)); > > + if (ret) > > + dev_pm_domain_detach(dev, true); > > + } > > > > - 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; > > } > > > > -- > > 2.7.4 > > > > Otherwise, this makes sense to me! > really thanks for your review! > Kind regards > Uffe
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); + } - 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; }