| Message ID | 20240102-j7200-pcie-s2r-v4-4-6f1f53390c85@bootlin.com |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | Add suspend to ram support for PCIe on J7200 | expand |
Hi! Sorry for being unresponsive. 2024-03-04 at 16:35, Thomas Richard wrote: > The mux_chip_resume() function restores a mux_chip using the cached state > of each mux. > > Signed-off-by: Thomas Richard <thomas.richard@bootlin.com> > --- > drivers/mux/core.c | 29 +++++++++++++++++++++++++++++ > include/linux/mux/driver.h | 1 + > 2 files changed, 30 insertions(+) > > diff --git a/drivers/mux/core.c b/drivers/mux/core.c > index 775816112932..0742aa2a7c73 100644 > --- a/drivers/mux/core.c > +++ b/drivers/mux/core.c > @@ -215,6 +215,35 @@ void mux_chip_free(struct mux_chip *mux_chip) > } > EXPORT_SYMBOL_GPL(mux_chip_free); > > +/** > + * mux_chip_resume() - restores the mux-chip state > + * @mux_chip: The mux-chip to resume. > + * > + * Restores the mux-chip state. > + * > + * Return: Zero on success or a negative errno on error. > + */ > +int mux_chip_resume(struct mux_chip *mux_chip) > +{ > + int ret, i; > + > + for (i = 0; i < mux_chip->controllers; ++i) { > + struct mux_control *mux = &mux_chip->mux[i]; > + > + if (mux->cached_state == MUX_CACHE_UNKNOWN) > + continue; > + > + ret = mux_control_set(mux, mux->cached_state); mux_control_set() is an internal helper. It is called from __mux_control_select() and mux_control_deselect() (and on init...) In all those cases, there is no race to reach the mux_control_set() function, by means of the mux->lock semaphore (or the mux not being "published" yet). I fail to see how resume is safe when mux->lock is ignored? Cheers, Peter > + if (ret < 0) { > + dev_err(&mux_chip->dev, "unable to restore state\n"); > + return ret; > + } > + } > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(mux_chip_resume); > + > static void devm_mux_chip_release(struct device *dev, void *res) > { > struct mux_chip *mux_chip = *(struct mux_chip **)res; > diff --git a/include/linux/mux/driver.h b/include/linux/mux/driver.h > index 18824064f8c0..2a7e5ec5d540 100644 > --- a/include/linux/mux/driver.h > +++ b/include/linux/mux/driver.h > @@ -88,6 +88,7 @@ struct mux_chip *mux_chip_alloc(struct device *dev, > int mux_chip_register(struct mux_chip *mux_chip); > void mux_chip_unregister(struct mux_chip *mux_chip); > void mux_chip_free(struct mux_chip *mux_chip); > +int mux_chip_resume(struct mux_chip *mux_chip); > > struct mux_chip *devm_mux_chip_alloc(struct device *dev, > unsigned int controllers, >
diff --git a/drivers/mux/core.c b/drivers/mux/core.c index 775816112932..0742aa2a7c73 100644 --- a/drivers/mux/core.c +++ b/drivers/mux/core.c @@ -215,6 +215,35 @@ void mux_chip_free(struct mux_chip *mux_chip) } EXPORT_SYMBOL_GPL(mux_chip_free); +/** + * mux_chip_resume() - restores the mux-chip state + * @mux_chip: The mux-chip to resume. + * + * Restores the mux-chip state. + * + * Return: Zero on success or a negative errno on error. + */ +int mux_chip_resume(struct mux_chip *mux_chip) +{ + int ret, i; + + for (i = 0; i < mux_chip->controllers; ++i) { + struct mux_control *mux = &mux_chip->mux[i]; + + if (mux->cached_state == MUX_CACHE_UNKNOWN) + continue; + + ret = mux_control_set(mux, mux->cached_state); + if (ret < 0) { + dev_err(&mux_chip->dev, "unable to restore state\n"); + return ret; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(mux_chip_resume); + static void devm_mux_chip_release(struct device *dev, void *res) { struct mux_chip *mux_chip = *(struct mux_chip **)res; diff --git a/include/linux/mux/driver.h b/include/linux/mux/driver.h index 18824064f8c0..2a7e5ec5d540 100644 --- a/include/linux/mux/driver.h +++ b/include/linux/mux/driver.h @@ -88,6 +88,7 @@ struct mux_chip *mux_chip_alloc(struct device *dev, int mux_chip_register(struct mux_chip *mux_chip); void mux_chip_unregister(struct mux_chip *mux_chip); void mux_chip_free(struct mux_chip *mux_chip); +int mux_chip_resume(struct mux_chip *mux_chip); struct mux_chip *devm_mux_chip_alloc(struct device *dev, unsigned int controllers,
The mux_chip_resume() function restores a mux_chip using the cached state of each mux. Signed-off-by: Thomas Richard <thomas.richard@bootlin.com> --- drivers/mux/core.c | 29 +++++++++++++++++++++++++++++ include/linux/mux/driver.h | 1 + 2 files changed, 30 insertions(+)