On Tue, Mar 13, 2018 at 2:25 PM, Vivek Gautam <vivek.gau...@codeaurora.org> wrote: > The lists managing the device-links can be traversed to > find the link between two devices. The device_link_add() APIs > does traverse these lists to check if there's already a link > setup between the two devices. > So, add a new APIs, device_link_find(), to find an existing > device link between two devices - suppliers and consumers. > > Signed-off-by: Vivek Gautam <vivek.gau...@codeaurora.org> > Cc: Rafael J. Wysocki <r...@rjwysocki.net> > Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> > --- > > * New patch added to this series. > > drivers/base/core.c | 30 +++++++++++++++++++++++++++--- > include/linux/device.h | 2 ++ > 2 files changed, 29 insertions(+), 3 deletions(-) > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index 5847364f25d9..e8c9774e4ba2 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -144,6 +144,30 @@ static int device_reorder_to_tail(struct device *dev, > void *not_used) > return 0; > } > > +/** > + * device_link_find - find any existing link between two devices. > + * @consumer: Consumer end of the link. > + * @supplier: Supplier end of the link. > + * > + * Returns pointer to the existing link between a supplier and > + * and consumer devices, or NULL if no link exists. > + */ > +struct device_link *device_link_find(struct device *consumer, > + struct device *supplier) > +{ > + struct device_link *link = NULL; > + > + if (!consumer || !supplier) > + return NULL; > + > + list_for_each_entry(link, &supplier->links.consumers, s_node) > + if (link->consumer == consumer) > + break; > + > + return link;
My bad, this too needs fixing (didn't add the changes to the patch :( ) list_for_each_entry(link, &supplier->links.consumers, s_node) if (link->consumer == consumer) return link; return NULL; > +} > +EXPORT_SYMBOL_GPL(device_link_find); > + > /** > * device_link_add - Create a link between two devices. > * @consumer: Consumer end of the link. > @@ -195,9 +219,9 @@ struct device_link *device_link_add(struct device > *consumer, > goto out; > } > > - list_for_each_entry(link, &supplier->links.consumers, s_node) > - if (link->consumer == consumer) > - goto out; > + link = device_link_find(consumer, supplier); > + if (link) > + goto out; > > link = kzalloc(sizeof(*link), GFP_KERNEL); > if (!link) > diff --git a/include/linux/device.h b/include/linux/device.h > index b093405ed525..13bc1884c3eb 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -1278,6 +1278,8 @@ extern const char *dev_driver_string(const struct > device *dev); > struct device_link *device_link_add(struct device *consumer, > struct device *supplier, u32 flags); > void device_link_del(struct device_link *link); > +struct device_link *device_link_find(struct device *consumer, > + struct device *supplier); > > #ifdef CONFIG_PRINTK > > -- > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member > of Code Aurora Forum, hosted by The Linux Foundation > > -- > To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation